update

AI_prompt.txt

@@ -51,3 +51,15 @@ Ecosystem Variance: Low-level native functions (e.g., NATS.connect(), JSON.read(
 
 
 
+
+
+
+I'm expanding this Julia package (NATSBridge) into a cross-platform project by adding a JavaScript and Python/MicroPython implementation. To ensure accuracy, the Julia src directory will serve as the ground truth, as the documentation may be outdated.
+
+My goal is to maintain interface parity at the high-level API for a consistent user experience, while ensuring the low-level implementation adheres strictly to the idiomatic conventions of each respective language (e.g., multiple dispatch in Julia vs. asynchronous, prototype, or class-based patterns in JS and Python/MicroPython)
+
+Now, help me do the following:
+1) check architecture.md for any mistake.
+
+
+

Project.toml

@@ -1,6 +1,6 @@
 name = "NATSBridge"
 uuid = "f2724d33-f338-4a57-b9f8-1be882570d10"
-version = "0.4.4"
+version = "0.4.5"
 authors = ["narawat <narawat@gmail.com>"]
 
 [deps]

README.md

@@ -1,6 +1,6 @@
-# NATSBridge
+# NATSBridge - Cross-Platform Bi-Directional Data Bridge
 
-A high-performance, bi-directional data bridge for **Julia** applications using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
+A high-performance, bi-directional data bridge for **Julia, JavaScript, Python, and MicroPython** applications using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
 
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 [![NATS](https://img.shields.io/badge/NATS-Enabled-green.svg)](https://nats.io)
@@ -10,6 +10,7 @@ A high-performance, bi-directional data bridge for **Julia** applications using
 ## Table of Contents
 
 - [Overview](#overview)
+- [Cross-Platform Support](#cross-platform-support)
 - [Features](#features)
 - [Architecture](#architecture)
 - [Installation](#installation)
@@ -17,7 +18,7 @@ A high-performance, bi-directional data bridge for **Julia** applications using
 - [API Reference](#api-reference)
 - [Payload Types](#payload-types)
 - [Transport Strategies](#transport-strategies)
-- [Examples](#examples)
+- [Cross-Platform Examples](#cross-platform-examples)
 - [Testing](#testing)
 - [License](#license)
 
@@ -25,7 +26,7 @@ A high-performance, bi-directional data bridge for **Julia** applications using
 
 ## Overview
 
-NATSBridge enables seamless communication for Julia applications through NATS, with intelligent transport selection based on payload size:
+NATSBridge enables seamless communication across multiple platforms through NATS, with intelligent transport selection based on payload size:
 
 | Transport | Payload Size | Method |
 |-----------|--------------|--------|
@@ -36,14 +37,40 @@ NATSBridge enables seamless communication for Julia applications through NATS, w
 
 - **Chat Applications**: Text, images, audio, video in a single message
 - **File Transfer**: Efficient transfer of large files using claim-check pattern
-- **Streaming Data**: Sensor data, telemetry, and analytics pipelines
+- **IoT/Embedded**: Sensor data, telemetry, and analytics pipelines (MicroPython)
+- **Cross-Platform Communication**: Interoperability between Julia, JavaScript, Python, and MicroPython systems
 
+---
+
+## Cross-Platform Support
+
+| Platform | Implementation | Features |
+|----------|----------------|----------|
+| **Julia** | [`src/NATSBridge.jl`](src/NATSBridge.jl) | Full feature set, Arrow IPC, multiple dispatch |
+| **JavaScript** | [`src/natsbridge.js`](src/natsbridge.js) | Node.js & browser, async/await |
+| **Python** | [`src/natsbridge.py`](src/natsbridge.py) | Desktop Python, asyncio, type hints |
+| **MicroPython** | [`src/natsbridge_mpy.py`](src/natsbridge_mpy.py) | Memory-constrained, synchronous API |
+
+### Platform Comparison
+
+| Feature | Julia | JavaScript | Python | MicroPython |
+|---------|-------|------------|--------|-------------|
+| Multiple Dispatch | ✅ Native | ❌ | ❌ | ❌ |
+| Async/Await | ❌ | ✅ Native | ✅ Native | ⚠️ (uasyncio) |
+| Type Safety | ✅ Strong | ⚠️ (TypeScript) | ✅ (Type hints) | ❌ |
+| Memory Management | ✅ GC | ✅ GC | ✅ GC | ⚠️ (Manual) |
+| Arrow IPC | ✅ Native | ✅ | ✅ | ❌ |
+| Direct Transport | ✅ | ✅ | ✅ | ✅ |
+| Link Transport | ✅ | ✅ | ✅ | ⚠️ (Limited) |
+| Handler Functions | ✅ | ✅ | ✅ | ✅ |
+| Cross-Platform API | ✅ | ✅ | ✅ | ✅ |
 
 ---
 
 ## Features
 
-- ✅ **Bi-directional messaging** for Julia applications
+- ✅ **Cross-platform messaging** for Julia, JavaScript, Python, and MicroPython applications
+- ✅ **Bi-directional messaging** with request-reply patterns
 - ✅ **Multi-payload support** - send multiple payloads with different types in one message
 - ✅ **Automatic transport selection** - direct vs link based on payload size
 - ✅ **Claim-Check pattern** for payloads > 1MB
@@ -51,8 +78,7 @@ NATSBridge enables seamless communication for Julia applications through NATS, w
 - ✅ **Exponential backoff** for reliable file server downloads
 - ✅ **Correlation ID tracking** for message tracing
 - ✅ **Reply-to support** for request-response patterns
-- ✅ **JetStream support** for message replay and durability
-
+- ✅ **Handler function abstraction** - pluggable file server implementations (Plik, AWS S3, custom)
 
 ---
 
@@ -62,13 +88,13 @@ NATSBridge enables seamless communication for Julia applications through NATS, w
 
 ```mermaid
 flowchart TB
-    subgraph Sender["Julia Application (Sender)"]
+    subgraph Sender["Application (Sender)"]
         SenderApp[App Code]
         NATSBridge_Send[NATSBridge]
         NATS_Client[<b>NATS.jl</b>]
     end
 
-    subgraph Receiver["Julia Application (Receiver)"]
+    subgraph Receiver["Application (Receiver)"]
         ReceiverApp[App Code]
         NATSBridge_Recv[NATSBridge]
         NATS_Client_Recv[<b>NATS.jl</b>]
@@ -96,14 +122,6 @@ flowchart TB
     style FileServer fill:#f3e5f5
 ```
 
-### Key Components
-
-| Component | Description |
-|-----------|-------------|
-| **Julia Application** | Sender and receiver applications using the NATSBridge module |
-| **NATS Server** | Message broker for transporting message envelopes |
-| **HTTP File Server** | Independent HTTP server for large payload storage (e.g., Plik) |
-
 ### Message Flow
 
 1. **Sender** creates a message envelope with payloads using `smartsend()`
@@ -124,11 +142,53 @@ The system uses handler functions to abstract file server operations:
 
 | Handler | Purpose |
 |---------|---------|
-| `plik_oneshot_upload()` | Uploads payload bytes to file server, returns URL |
-| `_fetch_with_backoff()` | Downloads data from URL with exponential backoff retry |
+| `plik_oneshot_upload()` / `plikOneshotUpload()` | Uploads payload bytes to file server, returns URL |
+| `_fetch_with_backoff()` / `fetchWithBackoff()` | Downloads data from URL with exponential backoff retry |
 
 This abstraction allows support for different file server implementations (Plik, AWS S3, custom HTTP server).
 
+### Message Envelope Schema
+
+All platforms use identical JSON schemas for message envelopes:
+
+```json
+{
+  "correlation_id": "uuid-v4-string",
+  "msg_id": "uuid-v4-string",
+  "timestamp": "2024-01-15T10:30:00Z",
+  "send_to": "topic/subject",
+  "msg_purpose": "ACK | NACK | updateStatus | shutdown | chat",
+  "sender_name": "agent-wine-web-frontend",
+  "sender_id": "uuid4",
+  "receiver_name": "agent-backend",
+  "receiver_id": "uuid4",
+  "reply_to": "topic",
+  "reply_to_msg_id": "uuid4",
+  "broker_url": "nats://localhost:4222",
+  "metadata": {},
+  "payloads": [
+    {
+      "id": "uuid4",
+      "dataname": "login_image",
+      "payload_type": "image",
+      "transport": "direct",
+      "encoding": "base64",
+      "size": 15433,
+      "data": "base64-encoded-string"
+    },
+    {
+      "id": "uuid4",
+      "dataname": "large_table",
+      "payload_type": "table",
+      "transport": "link",
+      "encoding": "none",
+      "size": 524288,
+      "data": "http://localhost:8080/file/UPLOAD_ID/FILE_ID/data.arrow"
+    }
+  ]
+}
+```
+
 ---
 
 ## Installation
@@ -138,14 +198,53 @@ This abstraction allows support for different file server implementations (Plik,
 - **NATS Server** (v2.10+ recommended)
 - **HTTP File Server** (optional, for payloads > 1MB)
 
-### Julia
+### Platform-Specific Dependencies
+
+#### Julia
 
 ```julia
 using Pkg
 Pkg.add("NATS")
-Pkg.add("https://git.yiem.cc/ton/NATSBridge")
+Pkg.add("Arrow")
+Pkg.add("JSON3")
+Pkg.add("HTTP")
+Pkg.add("UUIDs")
+Pkg.add("Dates")
 ```
 
+#### JavaScript (Node.js)
+
+```bash
+npm install nats uuid apache-arrow node-fetch
+# or
+yarn add nats uuid apache-arrow node-fetch
+```
+
+#### JavaScript (Browser)
+
+```bash
+npm install nats uuid apache-arrow
+# or use CDN:
+# https://unpkg.com/nats-js/dist/bundle/nats.min.js
+# https://unpkg.com/apache-arrow/arrow.min.js
+```
+
+#### Python (Desktop)
+
+```bash
+pip install nats-py aiohttp pyarrow pandas python-dateutil
+```
+
+#### MicroPython
+
+MicroPython uses built-in modules:
+- `network` - NATS connection (custom implementation)
+- `time` - Timestamps
+- `uos` - File operations
+- `base64` - Base64 encoding
+- `json` - JSON parsing
+- `struct` - Binary data handling
+
 ---
 
 ## Quick Start
@@ -166,61 +265,39 @@ mkdir -p /tmp/fileserver
 python3 -m http.server 8080 --directory /tmp/fileserver
 ```
 
-### Step 3: Send Your First Message
-
-#### Julia
-
-```julia
-using NATSBridge
-
-# Send a text message
-data = [("message", "Hello World", "text")]
-env, env_json_str = NATSBridge.smartsend("/chat/room1", data; broker_url="nats://localhost:4222")
-println("Message sent!")
-```
-
-### Step 4: Receive Messages
-
-#### Julia
-
-```julia
-using NATS, NATSBridge
-
-# Configuration
-const SUBJECT = "/chat/room1"
-const NATS_URL = "nats://localhost:4222"
-
-# Helper: Log with correlation ID
-function log_trace(message)
-    timestamp = Dates.now()
-    println("[$timestamp] $message")
-end
-
-# Receiver: Listen for messages - msg comes from the callback
-function test_receive()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
-        log_trace("Received message on $(msg.subject)")
-        
-        # Receive and process message
-        env, env_json_str = NATSBridge.smartreceive(msg, fileserverDownloadHandler)
-        for (dataname, data, type) in env["payloads"]
-            println("Received $dataname: $data")
-        end
-    end
-    
-    # Keep listening for 120 seconds
-    sleep(120)
-    NATS.drain(conn)
-end
-
-test_receive()
-```
-
 ---
 
 ## API Reference
 
+### Unified API Standard
+
+All platforms use the same input/output format for payloads:
+
+**Input format for smartsend:**
+```
+[(dataname1, data1, type1), (dataname2, data2, type2), ...]
+```
+
+**Output format for smartreceive:**
+```
+{
+  "correlation_id": "...",
+  "msg_id": "...",
+  "timestamp": "...",
+  "send_to": "...",
+  "msg_purpose": "...",
+  "sender_name": "...",
+  "sender_id": "...",
+  "receiver_name": "...",
+  "receiver_id": "...",
+  "reply_to": "...",
+  "reply_to_msg_id": "...",
+  "broker_url": "...",
+  "metadata": {...},
+  "payloads": [(dataname1, data1, type1), (dataname2, data2, type2), ...]
+}
+```
+
 ### smartsend
 
 Sends data either directly via NATS or via a fileserver URL, depending on payload size.
@@ -231,27 +308,96 @@ Sends data either directly via NATS or via a fileserver URL, depending on payloa
 using NATSBridge
 
 env, env_json_str = NATSBridge.smartsend(
-    subject,                           # NATS subject
+    subject::String,                           # NATS subject
     data::AbstractArray{Tuple{String, Any, String}};  # List of (dataname, data, type)
     broker_url::String = "nats://localhost:4222",
     fileserver_url = "http://localhost:8080",
     fileserver_upload_handler::Function = plik_oneshot_upload,
     size_threshold::Int = 1_000_000,
-    correlation_id::String = string(uuid4()),      # Correlation ID for tracing (auto-generated UUID)
+    correlation_id::String = string(uuid4()),
     msg_purpose::String = "chat",
     sender_name::String = "NATSBridge",
     receiver_name::String = "",
     receiver_id::String = "",
     reply_to::String = "",
     reply_to_msg_id::String = "",
-    is_publish::Bool = true,          # Whether to automatically publish to NATS
-    NATS_connection::Union{NATS.Connection, Nothing} = nothing,  # Pre-existing NATS connection (optional, saves connection overhead)
-    msg_id::String = string(uuid4()),  # Message ID (auto-generated UUID)
-    sender_id::String = string(uuid4())  # Sender ID (auto-generated UUID)
+    is_publish::Bool = true,
+    NATS_connection::Union{NATS.Connection, Nothing} = nothing,
+    msg_id::String = string(uuid4()),
+    sender_id::String = string(uuid4())
 )
-# Returns: (msgEnvelope_v1, JSON string)
-# - env: msgEnvelope_v1 object with all envelope metadata and payloads
-# - env_json_str: JSON string representation of the envelope for publishing
+# Returns: ::Tuple{msg_envelope_v1, String}
+```
+
+#### JavaScript
+
+```javascript
+const NATSBridge = require('natsbridge');
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    subject,
+    data,  // Array of [dataname, data, type] tuples
+    {
+        broker_url: 'nats://localhost:4222',
+        fileserver_url: 'http://localhost:8080',
+        fileserver_upload_handler: NATSBridge.plikOneshotUpload,
+        size_threshold: 1_000_000,
+        correlation_id: uuidv4(),
+        msg_purpose: 'chat',
+        sender_name: 'NATSBridge',
+        receiver_name: '',
+        receiver_id: '',
+        reply_to: '',
+        reply_to_msg_id: '',
+        is_publish: true,
+        nats_connection: null,
+        msg_id: uuidv4(),
+        sender_id: uuidv4()
+    }
+);
+// Returns: Promise<[env, env_json_str]>
+```
+
+#### Python
+
+```python
+from natsbridge import NATSBridge
+
+env, env_json_str = await NATSBridge.smartsend(
+    subject: str,
+    data: List[Tuple[str, Any, str]],
+    broker_url: str = "nats://localhost:4222",
+    fileserver_url: str = "http://localhost:8080",
+    fileserver_upload_handler: Callable = plik_oneshot_upload,
+    size_threshold: int = 1_000_000,
+    correlation_id: str = None,
+    msg_purpose: str = "chat",
+    sender_name: str = "NATSBridge",
+    receiver_name: str = "",
+    receiver_id: str = "",
+    reply_to: str = "",
+    reply_to_msg_id: str = "",
+    is_publish: bool = True,
+    nats_connection: Any = None,
+    msg_id: str = None,
+    sender_id: str = None
+)
+# Returns: Tuple[Dict, str]
+```
+
+#### MicroPython
+
+```python
+from natsbridge import NATSBridge
+
+# Limited to direct transport (< 100KB threshold)
+env, env_json_str = NATSBridge.smartsend(
+    subject,
+    data,  # List of (dataname, data, type) tuples
+    broker_url="nats://localhost:4222",
+    size_threshold=100000  # Lower threshold for memory constraints
+)
+# Returns: Tuple[Dict, str]
 ```
 
 ### smartreceive
@@ -263,7 +409,6 @@ Receives and processes messages from NATS, handling both direct and link transpo
 ```julia
 using NATSBridge
 
-# Note: msg is a NATS.Msg object passed from the subscription callback
 env = NATSBridge.smartreceive(
     msg::NATS.Msg;
     fileserver_download_handler::Function = _fetch_with_backoff,
@@ -271,51 +416,63 @@ env = NATSBridge.smartreceive(
     base_delay::Int = 100,
     max_delay::Int = 5000
 )
-# Returns: Dict with envelope metadata and payloads array
+# Returns: ::JSON.Object{String, Any}
 ```
 
-### publish_message
+#### JavaScript
 
-Publish a message to a NATS subject. This function is available in Julia with two overloads:
+```javascript
+const env = await NATSBridge.smartreceive(
+    msg,
+    {
+        fileserver_download_handler: NATSBridge.fetchWithBackoff,
+        max_retries: 5,
+        base_delay: 100,
+        max_delay: 5000
+    }
+);
+// Returns: Promise<env_object>
+```
 
-#### Julia
+#### Python
 
-**Using broker URL (creates new connection):**
-```julia
-using NATSBridge, NATS
-
-# Publish with URL - creates a new connection
-NATSBridge.publish_message(
-    "nats://localhost:4222",  # broker_url
-    "/chat/room1",            # subject
-    "{\"correlation_id\":\"abc123\"}",  # message
-    "abc123"                  # correlation_id
+```python
+env = await NATSBridge.smartreceive(
+    msg,
+    fileserver_download_handler=fetch_with_backoff,
+    max_retries=5,
+    base_delay=100,
+    max_delay=5000
 )
+# Returns: Dict with "payloads" key
 ```
 
-**Using pre-existing connection (saves connection overhead):**
-```julia
-using NATSBridge, NATS
+#### MicroPython
 
-# Create connection once and reuse
-conn = NATS.connect("nats://localhost:4222")
-NATSBridge.publish_message(conn, "/chat/room1", "{\"correlation_id\":\"abc123\"}", "abc123")
-# Connection is automatically drained after publish
+```python
+env = NATSBridge.smartreceive(
+    msg,
+    fileserver_download_handler=_sync_fileserver_download,
+    max_retries=3,
+    base_delay=100,
+    max_delay=1000
+)
+# Returns: Dict with "payloads" key
 ```
 
 ---
 
 ## Payload Types
 
-| Type | Description | Serialization |
-|------|-------------|---------------|
-| `text` | Plain text strings | UTF-8 bytes |
-| `dictionary` | JSON-serializable dictionaries | JSON |
-| `table` | Tabular data (DataFrames, arrays) | Apache Arrow IPC |
-| `image` | Image data (PNG, JPG) | Raw bytes |
-| `audio` | Audio data (WAV, MP3) | Raw bytes |
-| `video` | Video data (MP4, AVI) | Raw bytes |
-| `binary` | Generic binary data | Raw bytes |
+| Type | Julia | JavaScript | Python | MicroPython | Description |
+|------|-------|------------|--------|-------------|-------------|
+| `text` | `String` | `string` | `str` | `str` | Plain text strings |
+| `dictionary` | `Dict`, `NamedTuple` | `Object`, `Array` | `dict`, `list` | `dict` | JSON-serializable dictionaries |
+| `table` | `DataFrame`, `Arrow.Table` | `Array<Object>` | `pandas.DataFrame` | ❌ | Tabular data (Arrow IPC) |
+| `image` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Image data (PNG, JPG) |
+| `audio` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Audio data (WAV, MP3) |
+| `video` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Video data (MP4, AVI) |
+| `binary` | `Vector{UInt8}`, `IOBuffer` | `Uint8Array`, `Buffer` | `bytes`, `bytearray` | `bytearray` | Generic binary data |
 
 ---
 
@@ -325,31 +482,60 @@ NATSBridge.publish_message(conn, "/chat/room1", "{\"correlation_id\":\"abc123\"}
 
 Small payloads are sent directly via NATS with Base64 encoding.
 
-#### Julia
+#### Cross-Platform
+
 ```julia
+# Julia
 data = [("message", "Hello", "text")]
 smartsend("/topic", data)
 ```
 
+```javascript
+// JavaScript
+const data = [["message", "Hello", "text"]];
+smartsend("/topic", data);
+```
+
+```python
+# Python
+data = [("message", "Hello", "text")]
+await smartsend("/topic", data)
+```
+
 ### Link Transport (Payloads >= 1MB)
 
 Large payloads are uploaded to an HTTP file server.
 
-#### Julia
+#### Cross-Platform
+
 ```julia
+# Julia
 data = [("file", large_data, "binary")]
 smartsend("/topic", data; fileserver_url="http://localhost:8080")
 ```
 
+```javascript
+// JavaScript
+const data = [["file", largeData, "binary"]];
+smartsend("/topic", data, { fileserver_url: 'http://localhost:8080' });
+```
+
+```python
+# Python
+data = [("file", large_data, "binary")]
+await smartsend("/topic", data, fileserver_url="http://localhost:8080")
+```
+
 ---
 
-## Examples
+## Cross-Platform Examples
 
 ### Example 1: Chat with Mixed Content
 
-Send text, small image, and large file in one message.
+Send text, image, and large file in one message.
 
 #### Julia
+
 ```julia
 using NATSBridge
 
@@ -362,11 +548,48 @@ data = [
 env, env_json_str = NATSBridge.smartsend("/chat/room1", data; fileserver_url="http://localhost:8080")
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('natsbridge');
+
+const data = [
+    ["message_text", "Hello!", "text"],
+    ["user_avatar", imageData, "image"],
+    ["large_document", largeFileData, "binary"]
+];
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/chat/room1",
+    data,
+    { fileserver_url: 'http://localhost:8080' }
+);
+```
+
+#### Python
+
+```python
+from natsbridge import NATSBridge
+
+data = [
+    ("message_text", "Hello!", "text"),
+    ("user_avatar", image_data, "image"),
+    ("large_document", large_file_data, "binary")
+]
+
+env, env_json_str = await NATSBridge.smartsend(
+    "/chat/room1",
+    data,
+    fileserver_url="http://localhost:8080"
+)
+```
+
 ### Example 2: Dictionary Exchange
 
 Send configuration data between platforms.
 
 #### Julia
+
 ```julia
 using NATSBridge
 
@@ -380,11 +603,44 @@ data = [("config", config, "dictionary")]
 env, env_json_str = NATSBridge.smartsend("/device/config", data)
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('natsbridge');
+
+const config = {
+    wifi_ssid: "MyNetwork",
+    wifi_password: "password123",
+    update_interval: 60
+};
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/device/config",
+    [["config", config, "dictionary"]]
+);
+```
+
+#### Python
+
+```python
+from natsbridge import NATSBridge
+
+config = {
+    "wifi_ssid": "MyNetwork",
+    "wifi_password": "password123",
+    "update_interval": 60
+}
+
+data = [("config", config, "dictionary")]
+env, env_json_str = await NATSBridge.smartsend("/device/config", data)
+```
+
 ### Example 3: Table Data (Arrow IPC)
 
 Send tabular data using Apache Arrow IPC format.
 
 #### Julia
+
 ```julia
 using NATSBridge
 using DataFrames
@@ -399,14 +655,49 @@ data = [("students", df, "table")]
 env, env_json_str = NATSBridge.smartsend("/data/analysis", data)
 ```
 
-### Example 4: Request-Response Pattern with Envelope JSON
+#### JavaScript
 
-Bi-directional communication with reply-to support. The `smartsend` function now returns both the envelope object and a JSON string that can be published directly.
+```javascript
+const NATSBridge = require('natsbridge');
+
+const df = [
+    { id: 1, name: "Alice", score: 95 },
+    { id: 2, name: "Bob", score: 88 },
+    { id: 3, name: "Charlie", score: 92 }
+];
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/data/analysis",
+    [["students", df, "table"]]
+);
+```
+
+#### Python
+
+```python
+from natsbridge import NATSBridge
+import pandas as pd
+
+df = pd.DataFrame({
+    "id": [1, 2, 3],
+    "name": ["Alice", "Bob", "Charlie"],
+    "score": [95, 88, 92]
+})
+
+data = [("students", df, "table")]
+env, env_json_str = await NATSBridge.smartsend("/data/analysis", data)
+```
+
+### Example 4: Request-Response Pattern
+
+Bi-directional communication with reply-to support.
+
+#### Julia
 
-#### Julia (Requester)
 ```julia
 using NATSBridge
 
+# Requester
 env, env_json_str = NATSBridge.smartsend(
     "/device/command",
     [("command", Dict("action" => "read_sensor"), "dictionary")];
@@ -415,26 +706,20 @@ env, env_json_str = NATSBridge.smartsend(
 )
 ```
 
-#### Julia (Responder)
 ```julia
+# Responder
 using NATS, NATSBridge
 
-# Configuration
-const SUBJECT = "/device/command"
-const NATS_URL = "nats://localhost:4222"
-
 function test_responder()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
+    conn = NATS.connect("nats://localhost:4222")
+    NATS.subscribe(conn, "/device/command") do msg
         env = NATSBridge.smartreceive(msg, fileserver_download_handler=_fetch_with_backoff)
         
-        # Extract reply_to from the envelope metadata
         reply_to = env["reply_to"]
         
         for (dataname, data, type) in env["payloads"]
             if dataname == "command" && data["action"] == "read_sensor"
                 response = Dict("sensor_id" => "sensor-001", "value" => 42.5)
-                # Send response to the reply_to subject from the request
                 if !isempty(reply_to)
                     smartsend(reply_to, [("data", response, "dictionary")])
                 end
@@ -445,51 +730,118 @@ function test_responder()
     sleep(120)
     NATS.drain(conn)
 end
-
-test_responder()
 ```
 
-### Example 5: IoT Device Sensor Data
+#### JavaScript
 
-IoT device sending sensor data.
+```javascript
+const NATSBridge = require('natsbridge');
 
-#### Julia (Receiver)
-```julia
-using NATS, NATSBridge
+// Requester
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/device/command",
+    [["command", { action: "read_sensor" }, "dictionary"]],
+    { broker_url: 'nats://localhost:4222', reply_to: '/device/response' }
+);
+```
 
-# Configuration
-const SUBJECT = "/device/sensors"
-const NATS_URL = "nats://localhost:4222"
+```javascript
+// Responder
+const nats = require('nats');
+const NATSBridge = require('natsbridge');
 
-function test_receiver()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
-        env, env_json_str = NATSBridge.smartreceive(msg, fileserverDownloadHandler)
-        for (dataname, data, type) in env["payloads"]
-            if dataname == "temperature"
-                println("Temperature: $data")
-            elseif dataname == "humidity"
-                println("Humidity: $data")
-            end
-        end
-    end
+async function testResponder() {
+    const conn = await nats.connect('nats://localhost:4222');
     
-    sleep(120)
-    NATS.drain(conn)
-end
+    const subscription = await conn.subscribe('/device/command');
+    
+    for await (const msg of subscription) {
+        const env = await NATSBridge.smartreceive(msg, {
+            fileserver_download_handler: NATSBridge.fetchWithBackoff
+        });
+        
+        const replyTo = env.reply_to;
+        
+        for (const [dataname, data, type] of env.payloads) {
+            if (dataname === 'command' && data.action === 'read_sensor') {
+                const response = { sensor_id: 'sensor-001', value: 42.5 };
+                if (replyTo) {
+                    await NATSBridge.smartsend(
+                        replyTo,
+                        [["data", response, "dictionary"]]
+                    );
+                }
+            }
+        }
+    }
+    
+    setTimeout(() => conn.close(), 120000);
+}
+```
 
-test_receiver()
+#### Python
+
+```python
+from natsbridge import NATSBridge
+
+# Requester
+env, env_json_str = await NATSBridge.smartsend(
+    "/device/command",
+    [("command", {"action": "read_sensor"}, "dictionary")],
+    broker_url="nats://localhost:4222",
+    reply_to="/device/response"
+)
+```
+
+```python
+# Responder
+from natsbridge import NATSBridge
+import asyncio
+import nats
+
+async def test_responder():
+    nc = await nats.connect('nats://localhost:4222')
+    
+    async def msg_handler(msg):
+        env = await NATSBridge.smartreceive(
+            msg,
+            fileserver_download_handler=fetch_with_backoff
+        )
+        
+        reply_to = env["reply_to"]
+        
+        for dataname, data, type_ in env["payloads"]:
+            if dataname == "command" and data["action"] == "read_sensor":
+                response = {"sensor_id": "sensor-001", "value": 42.5}
+                if reply_to:
+                    await NATSBridge.smartsend(
+                        reply_to,
+                        [("data", response, "dictionary")]
+                    )
+    
+    await nc.subscribe('/device/command', cb=msg_handler)
+    
+    await asyncio.sleep(120)
+    await nc.drain()
 ```
 
 ---
 
 ## Testing
 
-Run the test scripts to verify functionality:
+### Test File Organization
 
-### Julia
+| Platform | Sender Tests | Receiver Tests |
+|----------|--------------|----------------|
+| **Julia** | `test/test_julia_*_sender.jl` | `test/test_julia_*_receiver.jl` |
+| **JavaScript** | `test/test_js_*_sender.js` | `test/test_js_*_receiver.js` |
+| **Python** | `test/test_py_*_sender.py` | `test/test_py_*_receiver.py` |
 
-```julia
+### Run Tests
+
+#### Julia
+
+```bash
 # Text message exchange
 julia test/test_julia_text_sender.jl
 julia test/test_julia_text_receiver.jl
@@ -511,6 +863,55 @@ julia test/test_julia_table_sender.jl
 julia test/test_julia_table_receiver.jl
 ```
 
+#### JavaScript (Node.js)
+
+```bash
+# Text message exchange
+node test/test_js_text_sender.js
+node test/test_js_text_receiver.js
+
+# Dictionary exchange
+node test/test_js_dictionary_sender.js
+node test/test_js_dictionary_receiver.js
+
+# Binary transfer
+node test/test_js_binary_sender.js
+node test/test_js_binary_receiver.js
+
+# Table exchange
+node test/test_js_table_sender.js
+node test/test_js_table_receiver.js
+```
+
+#### Python
+
+```bash
+# Text message exchange
+python3 test/test_py_text_sender.py
+python3 test/test_py_text_receiver.py
+
+# Dictionary exchange
+python3 test/test_py_dictionary_sender.py
+python3 test/test_py_dictionary_receiver.py
+
+# Binary transfer
+python3 test/test_py_binary_sender.py
+python3 test/test_py_binary_receiver.py
+
+# Table exchange
+python3 test/test_py_table_sender.py
+python3 test/test_py_table_receiver.py
+```
+
+---
+
+## Documentation
+
+For detailed architecture and implementation information, see:
+
+- [Architecture Documentation](docs/architecture.md) - Cross-platform architecture, API parity, platform-specific patterns
+- [Implementation Guide](docs/implementation.md) - Detailed implementation for each platform, handler functions, testing
+
 ---
 
 ## License

etc.jl

@@ -6,4 +6,33 @@ Requirements:
 
 Source of Truth: Treat the updated NATSbridge code as the definitive source. Update README.md to align exactly with these changes.
 API Consistency: Ensure the Main Package API (e.g., smartsend(), publish_message()) uses consistent naming across all three supported languages.
-Ecosystem Variance: Low-level native functions (e.g., NATS.connect(), JSON.read()) should follow the conventions of the specific language ecosystem and do not require cross-language consistency.
+Ecosystem Variance: Low-level native functions (e.g., NATS.connect(), JSON.read()) should follow the conventions of the specific language ecosystem and do not require cross-language consistency.
+
+
+
+
+
+
+
+
+
+
+
+
+
+Help me expands this Julia package (NATSBridge) into a cross-platform project by adding a JavaScript and Python/MicroPython implementation. To ensure accuracy,  NATSBridge.jl will serve as the ground truth, as the documentation may be outdated.
+
+My goal is to maintain interface parity at the high-level API for a consistent user experience, while ensuring the low-level implementation adheres strictly to the idiomatic conventions of each respective language (e.g., multiple dispatch in Julia vs. asynchronous, prototype, or class-based patterns in JS and Python/MicroPython)
+
+Now do the following:
+1) check docs to see if there is any mistake.
+
+
+
+
+
+
+
+
+
+

examples/tutorial.md

@@ -1,6 +1,6 @@
-# NATSBridge Tutorial
+# Cross-Platform NATSBridge Tutorial
 
-A step-by-step guide to get started with NATSBridge - a high-performance, bi-directional data bridge for **Julia**.
+A step-by-step guide to get started with NATSBridge across **Julia**, **JavaScript**, and **Python/MicroPython**.
 
 ## Table of Contents
 
@@ -15,22 +15,35 @@ A step-by-step guide to get started with NATSBridge - a high-performance, bi-dir
 
 ## Overview
 
-NATSBridge enables seamless communication for Julia applications through NATS, with automatic transport selection based on payload size:
+NATSBridge enables seamless communication across platforms through NATS, with automatic transport selection based on payload size:
 
 - **Direct Transport**: Payloads < 1MB are sent directly via NATS (Base64 encoded)
 - **Link Transport**: Payloads >= 1MB are uploaded to an HTTP file server and referenced via URL
 
+### Cross-Platform API Parity
+
+All three platforms use the same high-level API:
+
+```
+# Input format
+smartsend(subject, [(dataname, data, type), ...], options)
+
+# Output format
+(env, env_json_str) = smartsend(...)
+env = smartreceive(msg, options)
+```
+
 ### Supported Payload Types
 
-| Type | Description |
-|------|-------------|
-| `text` | Plain text strings |
-| `dictionary` | JSON-serializable dictionaries |
-| `table` | Tabular data (Arrow IPC format) |
-| `image` | Image data (PNG, JPG bytes) |
-| `audio` | Audio data (WAV, MP3 bytes) |
-| `video` | Video data (MP4, AVI bytes) |
-| `binary` | Generic binary data |
+| Type | Julia | JavaScript | Python | MicroPython |
+|------|-------|------------|--------|-------------|
+| `text` | `String` | `string` | `str` | `str` |
+| `dictionary` | `Dict` | `Object` | `dict` | `dict` |
+| `table` | `DataFrame` | `Array<Object>` | `DataFrame` | ❌ |
+| `image` | `Vector{UInt8}` | `Uint8Array` | `bytes` | `bytearray` |
+| `audio` | `Vector{UInt8}` | `Uint8Array` | `bytes` | `bytearray` |
+| `video` | `Vector{UInt8}` | `Uint8Array` | `bytes` | `bytearray` |
+| `binary` | `Vector{UInt8}` | `Uint8Array` | `bytes` | `bytearray` |
 
 ---
 
@@ -40,7 +53,7 @@ Before you begin, ensure you have:
 
 1. **NATS Server** running (or accessible)
 2. **HTTP File Server** (optional, for large payloads > 1MB)
-3. **Julia** with required packages
+3. **Platform-specific packages** installed
 
 ---
 
@@ -58,6 +71,29 @@ Pkg.add("UUIDs")
 Pkg.add("Dates")
 ```
 
+### JavaScript (Node.js)
+
+```bash
+npm install nats uuid apache-arrow node-fetch
+```
+
+### JavaScript (Browser)
+
+```html
+<script src="https://unpkg.com/nats-js/dist/bundle/nats.min.js"></script>
+<script src="https://unpkg.com/apache-arrow/arrow.min.js"></script>
+```
+
+### Python (Desktop)
+
+```bash
+pip install nats-py aiohttp pyarrow pandas
+```
+
+### MicroPython
+
+Uses built-in modules: `network`, `socket`, `time`, `json`, `base64`
+
 ---
 
 ## Quick Start
@@ -71,10 +107,7 @@ docker run -p 4222:4222 nats:latest
 ### Step 2: Start HTTP File Server (Optional)
 
 ```bash
-# Create a directory for file uploads
 mkdir -p /tmp/fileserver
-
-# Use any HTTP server that supports POST for file uploads
 python3 -m http.server 8080 --directory /tmp/fileserver
 ```
 
@@ -88,16 +121,84 @@ using NATSBridge
 # Send a text message
 data = [("message", "Hello World", "text")]
 env, env_json_str = smartsend("/chat/room1", data, broker_url="nats://localhost:4222")
-# env: msg_envelope_v1 object with all metadata and payloads
+# env: msg_envelope_v1 struct with all metadata and payloads
 # env_json_str: JSON string representation of the envelope for publishing
 println("Message sent!")
 
 # Or use is_publish=false to get envelope and JSON without publishing
 env, env_json_str = smartsend("/chat/room1", data, broker_url="nats://localhost:4222", is_publish=false)
-# env: msg_envelope_v1 object
+# env: msg_envelope_v1 struct
 # env_json_str: JSON string for publishing to NATS
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+
+// Send a text message
+const data = [["message", "Hello World", "text"]];
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/chat/room1",
+    data,
+    { broker_url: "nats://localhost:4222" }
+);
+// env: Object with all metadata and payloads
+// env_json_str: JSON string for publishing
+console.log("Message sent!");
+
+// Or use is_publish=false
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/chat/room1",
+    data,
+    { broker_url: "nats://localhost:4222", is_publish: false }
+);
+```
+
+#### Python
+
+```python
+from natsbridge import smartsend
+
+# Send a text message
+data = [("message", "Hello World", "text")]
+env, env_json_str = await smartsend(
+    "/chat/room1",
+    data,
+    broker_url="nats://localhost:4222"
+)
+# env: Dict with all metadata and payloads
+# env_json_str: JSON string for publishing
+print("Message sent!")
+
+# Or use is_publish=False
+env, env_json_str = await smartsend(
+    "/chat/room1",
+    data,
+    broker_url="nats://localhost:4222",
+    is_publish=False
+)
+# env: Dict with all metadata and payloads
+# env_json_str: JSON string for publishing to NATS
+```
+
+#### MicroPython
+
+```python
+from natsbridge_mpy import NATSBridge
+
+bridge = NATSBridge()
+
+# Send a text message (limited to small payloads)
+data = [("message", "Hello World", "text")]
+env, env_json_str = bridge.smartsend(
+    "/chat/room1",
+    data,
+    size_threshold=100000  # Lower threshold for MicroPython
+)
+print("Message sent!")
+```
+
 ### Step 4: Receive Messages
 
 #### Julia
@@ -107,11 +208,43 @@ using NATSBridge
 
 # Receive and process message
 env = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff)
+# Returns: ::JSON.Object{String, Any} with "payloads" field containing Vector{Tuple{String, Any, String}}
+# Access payloads: for (dataname, data, type) in env["payloads"]
 for (dataname, data, type) in env["payloads"]
     println("Received $dataname: $data")
 end
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+
+// Receive and process message
+const env = await NATSBridge.smartreceive(msg, {
+    fileserver_download_handler: NATSBridge.fetchWithBackoff
+});
+// env.payloads = [[dataname, data, type], ...]
+for (const [dataname, data, type] of env.payloads) {
+    console.log(`Received ${dataname}:`, data);
+}
+```
+
+#### Python
+
+```python
+from natsbridge import smartreceive, fetch_with_backoff
+
+# Receive and process message
+env = await smartreceive(
+    msg,
+    fileserver_download_handler=fetch_with_backoff
+)
+# env["payloads"] = [(dataname, data, type), ...]
+for dataname, data, type_ in env["payloads"]:
+    print(f"Received {dataname}: {data}")
+```
+
 ---
 
 ## Basic Examples
@@ -133,6 +266,65 @@ data = [("config", config, "dictionary")]
 env, env_json_str = smartsend("/device/config", data, broker_url="nats://localhost:4222")
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+
+const config = {
+    wifi_ssid: "MyNetwork",
+    wifi_password: "password123",
+    update_interval: 60
+};
+
+const data = [["config", config, "dictionary"]];
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/device/config",
+    data,
+    { broker_url: "nats://localhost:4222" }
+);
+```
+
+#### Python
+
+```python
+from natsbridge import smartsend
+
+config = {
+    "wifi_ssid": "MyNetwork",
+    "wifi_password": "password123",
+    "update_interval": 60
+}
+
+data = [("config", config, "dictionary")]
+env, env_json_str = await smartsend(
+    "/device/config",
+    data,
+    broker_url="nats://localhost:4222"
+)
+```
+
+#### MicroPython
+
+```python
+from natsbridge_mpy import NATSBridge
+
+bridge = NATSBridge()
+
+config = {
+    "wifi_ssid": "MyNetwork",
+    "wifi_password": "password123",
+    "update_interval": 60
+}
+
+data = [("config", config, "dictionary")]
+env, env_json_str = bridge.smartsend(
+    "/device/config",
+    data,
+    size_threshold=100000
+)
+```
+
 ### Example 2: Sending Binary Data (Image)
 
 #### Julia
@@ -147,6 +339,59 @@ data = [("user_image", image_data, "binary")]
 env, env_json_str = smartsend("/chat/image", data, broker_url="nats://localhost:4222")
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+const fs = require('fs');
+
+// Read image file
+const image_data = fs.readFileSync('image.png');
+
+const data = [["user_image", image_data, "binary"]];
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/chat/image",
+    data,
+    { broker_url: "nats://localhost:4222" }
+);
+```
+
+#### Python
+
+```python
+from natsbridge import smartsend
+
+# Read image file
+with open("image.png", "rb") as f:
+    image_data = f.read()
+
+data = [("user_image", image_data, "binary")]
+env, env_json_str = await smartsend(
+    "/chat/image",
+    data,
+    broker_url="nats://localhost:4222"
+)
+```
+
+#### MicroPython
+
+```python
+from natsbridge_mpy import NATSBridge
+
+bridge = NATSBridge()
+
+# Read image file
+with open("image.png", "rb") as f:
+    image_data = f.read()
+
+data = [("user_image", image_data, "binary")]
+env, env_json_str = bridge.smartsend(
+    "/chat/image",
+    data,
+    size_threshold=100000
+)
+```
+
 ### Example 3: Request-Response Pattern
 
 #### Julia (Requester)
@@ -163,16 +408,47 @@ env, env_json_str = smartsend(
     reply_to="/device/response",
     reply_to_msg_id="cmd-001"
 )
-# env: msg_envelope_v1 object
-# env_json_str: JSON string for publishing to NATS
+```
+
+#### JavaScript (Requester)
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+
+// Send command with reply-to
+const data = [["command", { action: "read_sensor" }, "dictionary"]];
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/device/command",
+    data,
+    {
+        broker_url: "nats://localhost:4222",
+        reply_to: "/device/response",
+        reply_to_msg_id: "cmd-001"
+    }
+);
+```
+
+#### Python (Requester)
+
+```python
+from natsbridge import smartsend
+
+# Send command with reply-to
+data = [("command", {"action": "read_sensor"}, "dictionary")]
+env, env_json_str = await smartsend(
+    "/device/command",
+    data,
+    broker_url="nats://localhost:4222",
+    reply_to="/device/response",
+    reply_to_msg_id="cmd-001"
+)
 ```
 
 #### Julia (Responder)
 
 ```julia
-using NATS, NATSBridge
+using NATSBridge, NATS
 
-# Configuration
 const SUBJECT = "/device/command"
 const NATS_URL = "nats://localhost:4222"
 
@@ -181,13 +457,11 @@ function test_responder()
     NATS.subscribe(conn, SUBJECT) do msg
         env = smartreceive(msg, fileserver_download_handler=_fetch_with_backoff)
         
-        # Extract reply_to from the envelope metadata
         reply_to = env["reply_to"]
         
         for (dataname, data, type) in env["payloads"]
             if dataname == "command" && data["action"] == "read_sensor"
                 response = Dict("sensor_id" => "sensor-001", "value" => 42.5)
-                # Send response to the reply_to subject from the request
                 if !isempty(reply_to)
                     smartsend(reply_to, [("data", response, "dictionary")])
                 end
@@ -225,8 +499,73 @@ env, env_json_str = smartsend(
     fileserver_url="http://localhost:8080"
 )
 
-# The envelope will contain the download URL
 println("File uploaded to: $(env.payloads[1].data)")
+# Note: For link transport, data field contains the URL string
+```
+
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+
+// Create large data (> 1MB)
+const large_data = Buffer.alloc(2_000_000);
+for (let i = 0; i < large_data.length; i++) {
+    large_data[i] = Math.floor(Math.random() * 256);
+}
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/data/large",
+    [["large_file", large_data, "binary"]],
+    {
+        broker_url: "nats://localhost:4222",
+        fileserver_url: "http://localhost:8080"
+    }
+);
+
+console.log("File uploaded to:", env.payloads[0].data);
+// Note: For link transport, data field contains the URL string
+```
+
+#### Python
+
+```python
+from natsbridge import smartsend
+
+# Create large data (> 1MB)
+import os
+large_data = os.urandom(2_000_000)
+
+env, env_json_str = await smartsend(
+    "/data/large",
+    [("large_file", large_data, "binary")],
+    broker_url="nats://localhost:4222",
+    fileserver_url="http://localhost:8080"
+)
+
+print(f"File uploaded to: {env['payloads'][0]['data']}")
+# Note: For link transport, data field contains the URL string
+```
+
+#### MicroPython
+
+MicroPython enforces a hard limit of 50KB per payload:
+
+```python
+from natsbridge_mpy import NATSBridge
+
+bridge = NATSBridge()
+
+# MicroPython has a hard limit of 50KB per payload
+# Use streaming or chunking for larger data
+small_data = bytes(1000)  # 1KB
+
+data = [("small_file", small_data, "binary")]
+env, env_json_str = bridge.smartsend(
+    "/data/small",
+    data,
+    size_threshold=100000  # Enforced max: 50000 bytes
+)
 ```
 
 ### Example 5: Mixed Content (Chat with Text + Image)
@@ -248,6 +587,47 @@ data = [
 env, env_json_str = smartsend("/chat/mixed", data, broker_url="nats://localhost:4222")
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+const fs = require('fs');
+
+const image_data = fs.readFileSync('avatar.png');
+
+const data = [
+    ["message_text", "Hello with image!", "text"],
+    ["user_avatar", image_data, "image"]
+];
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/chat/mixed",
+    data,
+    { broker_url: "nats://localhost:4222" }
+);
+```
+
+#### Python
+
+```python
+from natsbridge import smartsend
+
+with open("avatar.png", "rb") as f:
+    image_data = f.read()
+
+data = [
+    ("message_text", "Hello with image!", "text"),
+    ("user_avatar", image_data, "image")
+]
+
+env, env_json_str = await smartsend(
+    "/chat/mixed",
+    data,
+    broker_url="nats://localhost:4222"
+)
+# env: Dict with all metadata and payloads
+```
+
 ### Example 6: Table Data (Arrow IPC)
 
 For tabular data, NATSBridge uses Apache Arrow IPC format:
@@ -269,12 +649,58 @@ data = [("students", df, "table")]
 env, env_json_str = smartsend("/data/students", data, broker_url="nats://localhost:4222")
 ```
 
+#### JavaScript
+
+```javascript
+const NATSBridge = require('./src/natsbridge.js');
+
+// Create table data (array of objects)
+const table_data = [
+    { id: 1, name: "Alice", score: 95 },
+    { id: 2, name: "Bob", score: 88 },
+    { id: 3, name: "Charlie", score: 92 }
+];
+
+const data = [["students", table_data, "table"]];
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/data/students",
+    data,
+    { broker_url: "nats://localhost:4222" }
+);
+```
+
+#### Python
+
+```python
+from natsbridge import smartsend
+import pandas as pd
+
+# Create DataFrame
+df = pd.DataFrame({
+    'id': [1, 2, 3],
+    'name': ['Alice', 'Bob', 'Charlie'],
+    'score': [95, 88, 92]
+})
+
+data = [("students", df, "table")]
+env, env_json_str = await smartsend(
+    "/data/students",
+    data,
+    broker_url="nats://localhost:4222"
+)
+```
+
+#### MicroPython
+
+MicroPython does not support table type due to memory constraints. Use dictionary or binary instead.
+
 ---
 
 ## Next Steps
 
 1. **Explore the test directory** for more examples
 2. **Check the documentation** for advanced configuration options
+3. **Read the walkthrough** for building real-world applications
 
 ---
 
@@ -295,7 +721,8 @@ env, env_json_str = smartsend("/data/students", data, broker_url="nats://localho
 ### Serialization Errors
 
 - Verify data type matches the specified type
-- Check that binary data is in the correct format (Vector{UInt8})
+- Check that binary data is in the correct format
+- MicroPython: Ensure payload size < 50KB
 
 ---
 

package.json

@@ -1,28 +0,0 @@
-{
-	"name": "natsbridge",
-	"version": "1.0.0",
-	"description": "Bi-Directional Data Bridge for JavaScript using NATS",
-	"main": "src/NATSBridge.js",
-	"scripts": {
-		"test": "echo \"Error: no test specified\" && exit 1",
-		"lint": "eslint src/*.js test/*.js"
-	},
-	"keywords": [
-		"nats",
-		"message-broker",
-		"bridge",
-		"arrow",
-		"serialization"
-	],
-	"author": "",
-	"license": "MIT",
-	"dependencies": {
-		"nats": "^2.9.0",
-		"apache-arrow": "^14.0.0",
-		"uuid": "^9.0.0"
-	},
-	"devDependencies": {
-		"eslint": "^8.0.0",
-		"jest": "^29.0.0"
-	}
-}

src/NATSBridge.jl

@@ -279,42 +279,38 @@ function envelope_to_json(env::msg_envelope_v1)
     "broker_url" => env.broker_url
   )
   
-  if !isempty(env.metadata)  # Only include metadata if it exists and is not empty
-    obj["metadata"] = Dict(String(k) => v for (k, v) in env.metadata)
-  end
+  obj["metadata"] = Dict(String(k) => v for (k, v) in env.metadata)
   
   # Convert payloads to JSON array
-  if !isempty(env.payloads)
-    payloads_json = []
-    for payload in env.payloads
-      payload_obj = Dict{String, Any}(
-        "id" => payload.id,
-        "dataname" => payload.dataname,
-        "payload_type" => payload.payload_type,
-        "transport" => payload.transport,
-        "encoding" => payload.encoding,
-        "size" => payload.size,
-      )
-      # Include data based on transport type
-        if payload.transport == "direct" && payload.data !== nothing
-          if payload.encoding == "base64" || payload.encoding == "json"
-            payload_obj["data"] = payload.data
-          else
-            # For other encodings, use base64
-            payload_bytes = _get_payload_bytes(payload.data)
-            payload_obj["data"] = Base64.base64encode(payload_bytes)
-          end
-        elseif payload.transport == "link" && payload.data !== nothing
-          # For link transport, data is a URL string - include directly
+  payloads_json = []
+  for payload in env.payloads
+    payload_obj = Dict{String, Any}(
+      "id" => payload.id,
+      "dataname" => payload.dataname,
+      "payload_type" => payload.payload_type,
+      "transport" => payload.transport,
+      "encoding" => payload.encoding,
+      "size" => payload.size,
+    )
+    # Include data based on transport type
+      if payload.transport == "direct" && payload.data !== nothing
+        if payload.encoding == "base64" || payload.encoding == "json"
           payload_obj["data"] = payload.data
+        else
+          # For other encodings, use base64
+          payload_bytes = _get_payload_bytes(payload.data)
+          payload_obj["data"] = Base64.base64encode(payload_bytes)
         end
-      if !isempty(payload.metadata)
-        payload_obj["metadata"] = Dict(String(k) => v for (k, v) in payload.metadata)
+      elseif payload.transport == "link" && payload.data !== nothing
+        # For link transport, data is a URL string - include directly
+        payload_obj["data"] = payload.data
       end
-      push!(payloads_json, payload_obj)
+    if !isempty(payload.metadata)
+      payload_obj["metadata"] = Dict(String(k) => v for (k, v) in payload.metadata)
     end
-    obj["payloads"] = payloads_json
+    push!(payloads_json, payload_obj)
   end
+  obj["payloads"] = payloads_json
   
   JSON.json(obj)
 end
@@ -388,7 +384,7 @@ Each payload can have a different type, enabling mixed-content messages (e.g., c
    - `sender_id::String = string(uuid4())` - Sender ID (auto-generated UUID if not provided)
 
 # Return:
-  - A tuple `(env, env_json_str)` where:
+  - `::Tuple{msg_envelope_v1, String}` - A tuple containing:
     - `env::msg_envelope_v1` - The envelope object containing all metadata and payloads
     - `env_json_str::String` - JSON string representation of the envelope for publishing
 
@@ -447,7 +443,7 @@ function smartsend(
   NATS_connection::Union{NATS.Connection, Nothing} = nothing,  # a provided connection saves establishing connection overhead.
   msg_id::String = string(uuid4()),  # Message ID
   sender_id::String = string(uuid4())  # Sender ID
-) where {T1<:Any}
+)::Tuple{msg_envelope_v1, String} where {T1<:Any}
 
   # Log start of send operation
   log_trace(correlation_id, "Starting smartsend for subject: $subject")
@@ -754,14 +750,14 @@ A HTTP file server is required along with its download function.
   - `max_delay::Int = 5000` - Maximum delay for exponential backoff in ms
 
 # Return:
-   - JSON object of envelope with list of (dataname, data, data_type) tuples in payloads field
+   - `::JSON.Object{String, Any}` - key-value structure resemble msg_envelope_v1
 
 # Example
 ```jldoctest
 # Receive and process message
 msg = nats_message  # NATS message
-payloads = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff, max_retries=5, base_delay=100, max_delay=5000)
-# payloads = [("dataname1", data1, "type1"), ("dataname2", data2, "type2"), ...]
+env = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff, max_retries=5, base_delay=100, max_delay=5000)
+# env["payloads"] = [("dataname1", data1, "type1"), ("dataname2", data2, "type2"), ...]
 ```
 """
 function smartreceive(
@@ -770,7 +766,7 @@ function smartreceive(
   max_retries::Int = 5,
   base_delay::Int = 100,
   max_delay::Int = 5000
-)
+)::JSON.Object{String, Any}
   # Parse the JSON envelope
   env_json_obj = JSON.parse(String(msg.payload))
   log_trace(env_json_obj["correlation_id"], "Processing received message")  # Log message processing start
@@ -818,7 +814,7 @@ function smartreceive(
     end
   end
   env_json_obj["payloads"] = payloads_list
-  return env_json_obj  # JSON object of envelope with list of (dataname, data, data_type) tuples in payloads field
+  return env_json_obj  # key-value structure resemble msg_envelope_v1
 end
 
 

src/natsbridge.js

@@ -0,0 +1,674 @@
+/**
+ * NATSBridge - Cross-Platform Bi-Directional Data Bridge
+ * JavaScript/Node.js Implementation
+ * 
+ * This module provides functionality for sending and receiving data across network boundaries
+ * using NATS as the message bus, with support for both direct payload transport and
+ * URL-based transport for larger payloads.
+ * 
+ * @module NATSBridge
+ */
+
+const nats = require('nats');
+const { v4: uuidv4 } = require('uuid');
+const fetch = require('node-fetch');
+const arrow = require('apache-arrow');
+
+// ---------------------------------------------- Constants ---------------------------------------------- //
+
+/**
+ * Default size threshold for switching from direct to link transport (1MB)
+ */
+const DEFAULT_SIZE_THRESHOLD = 1_000_000;
+
+/**
+ * Default NATS server URL
+ */
+const DEFAULT_BROKER_URL = 'nats://localhost:4222';
+
+/**
+ * Default HTTP file server URL for link transport
+ */
+const DEFAULT_FILESERVER_URL = 'http://localhost:8080';
+
+// ---------------------------------------------- Utility Functions ---------------------------------------------- //
+
+/**
+ * Convert Buffer to Base64 string
+ * @param {Buffer} buffer - Buffer to encode
+ * @returns {string} Base64 encoded string
+ */
+function bufferToBase64(buffer) {
+    return buffer.toString('base64');
+}
+
+/**
+ * Log a trace message with correlation ID and timestamp
+ * @param {string} correlationId - Correlation ID for tracing
+ * @param {string} message - Message content to log
+ */
+function logTrace(correlationId, message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] [Correlation: ${correlationId}] ${message}`);
+}
+
+// ---------------------------------------------- Serialization Functions ---------------------------------------------- //
+
+/**
+ * Serialize data according to specified format
+ * @param {any} data - Data to serialize
+ * @param {string} payloadType - Target format: "text", "dictionary", "table", "image", "audio", "video", "binary"
+ * @returns {Buffer} Binary representation of the serialized data
+ */
+async function serializeData(data, payloadType) {
+    if (payloadType === 'text') {
+        if (typeof data === 'string') {
+            return Buffer.from(data, 'utf8');
+        } else {
+            throw new Error('Text data must be a string');
+        }
+    } else if (payloadType === 'dictionary') {
+        const jsonStr = JSON.stringify(data);
+        return Buffer.from(jsonStr, 'utf8');
+    } else if (payloadType === 'table') {
+        // Convert array of objects to Arrow IPC format
+        if (!Array.isArray(data) || data.length === 0) {
+            throw new Error('Table data must be a non-empty array of objects');
+        }
+        
+        return serializeArrowTable(data);
+    } else if (payloadType === 'image') {
+        if (data instanceof Uint8Array || Buffer.isBuffer(data)) {
+            return Buffer.from(data);
+        } else {
+            throw new Error('Image data must be Uint8Array or Buffer');
+        }
+    } else if (payloadType === 'audio') {
+        if (data instanceof Uint8Array || Buffer.isBuffer(data)) {
+            return Buffer.from(data);
+        } else {
+            throw new Error('Audio data must be Uint8Array or Buffer');
+        }
+    } else if (payloadType === 'video') {
+        if (data instanceof Uint8Array || Buffer.isBuffer(data)) {
+            return Buffer.from(data);
+        } else {
+            throw new Error('Video data must be Uint8Array or Buffer');
+        }
+    } else if (payloadType === 'binary') {
+        if (data instanceof Uint8Array || Buffer.isBuffer(data)) {
+            return Buffer.from(data);
+        } else {
+            throw new Error('Binary data must be Uint8Array or Buffer');
+        }
+    } else {
+        throw new Error(`Unknown payload_type: ${payloadType}`);
+    }
+}
+
+/**
+ * Helper function to properly serialize table data to Arrow IPC
+ * @param {Array<Object>} data - Array of objects representing table rows
+ * @returns {Buffer} Arrow IPC formatted buffer
+ */
+function serializeArrowTable(data) {
+    if (!Array.isArray(data) || data.length === 0) {
+        throw new Error('Table data must be a non-empty array of objects');
+    }
+    
+    // Build schema from first row
+    const fields = Object.keys(data[0]).map(key => {
+        const value = data[0][key];
+        let arrowType;
+        if (typeof value === 'number') {
+            arrowType = Number.isInteger(value) ? arrow.Int64 : arrow.Float64;
+        } else if (typeof value === 'boolean') {
+            arrowType = arrow.Boolean;
+        } else if (value instanceof Date) {
+            arrowType = arrow.Date;
+        } else {
+            arrowType = arrow.Utf8;
+        }
+        return new arrow.Field(key, arrowType, true);
+    });
+    
+    const schema = new arrow.Schema(fields);
+    const batches = [];
+    
+    // Create record batches
+    for (const row of data) {
+        const batch = arrow.recordBatch.fromObjects([row], schema);
+        batches.push(batch);
+    }
+    
+    // Write to buffer using IPC format
+    const buffers = arrow.ipc.recordBatchesToMessage(batches, schema).buffers;
+    const combined = new Uint8Array(buffers.reduce((acc, b) => acc + b.byteLength, 0));
+    let offset = 0;
+    for (const buf of buffers) {
+        combined.set(new Uint8Array(buf), offset);
+        offset += buf.byteLength;
+    }
+    
+    return Buffer.from(combined);
+}
+
+/**
+ * Deserialize bytes to data based on type
+ * @param {Buffer|Uint8Array} data - Serialized data as bytes
+ * @param {string} payloadType - Data type
+ * @param {string} correlationId - Correlation ID for logging
+ * @returns {any} Deserialized data
+ */
+async function deserializeData(data, payloadType, correlationId) {
+    const buffer = Buffer.isBuffer(data) ? data : Buffer.from(data);
+    
+    if (payloadType === 'text') {
+        return buffer.toString('utf8');
+    } else if (payloadType === 'dictionary') {
+        const jsonStr = buffer.toString('utf8');
+        return JSON.parse(jsonStr);
+    } else if (payloadType === 'table') {
+        const table = arrow.tableFromRawBytes(buffer);
+        return table;
+    } else if (payloadType === 'image') {
+        return buffer;
+    } else if (payloadType === 'audio') {
+        return buffer;
+    } else if (payloadType === 'video') {
+        return buffer;
+    } else if (payloadType === 'binary') {
+        return buffer;
+    } else {
+        throw new Error(`Unknown payload_type: ${payloadType}`);
+    }
+}
+
+// ---------------------------------------------- File Server Handlers ---------------------------------------------- //
+
+/**
+ * Upload data to plik server in one-shot mode
+ * @param {string} fileServerUrl - Base URL of the plik server
+ * @param {string} dataname - Name of the file being uploaded
+ * @param {Buffer|Uint8Array} data - Raw byte data of the file content
+ * @returns {Promise<{status: number, uploadid: string, fileid: string, url: string}>}
+ */
+async function plikOneshotUpload(fileServerUrl, dataname, data) {
+    const buffer = Buffer.isBuffer(data) ? data : Buffer.from(data);
+    
+    // Get upload id
+    const urlGetUploadID = `${fileServerUrl}/upload`;
+    const headers = { 'Content-Type': 'application/json' };
+    const body = JSON.stringify({ OneShot: true });
+    
+    const httpResponse = await fetch(urlGetUploadID, {
+        method: 'POST',
+        headers,
+        body
+    });
+    
+    const responseJson = await httpResponse.json();
+    const uploadid = responseJson.id;
+    const uploadtoken = responseJson.uploadToken;
+
+    // Upload file
+    const urlUpload = `${fileServerUrl}/file/${uploadid}`;
+    const form = new FormData();
+    const blob = new Blob([buffer], { type: 'application/octet-stream' });
+    form.append('file', blob, dataname);
+    
+    const uploadHeaders = {
+        'X-UploadToken': uploadtoken
+    };
+
+    const uploadResponse = await fetch(urlUpload, {
+        method: 'POST',
+        headers: uploadHeaders,
+        body: form
+    });
+    
+    const uploadJson = await uploadResponse.json();
+    const fileid = uploadJson.id;
+
+    const url = `${fileServerUrl}/file/${uploadid}/${fileid}/${dataname}`;
+
+    return {
+        status: uploadResponse.status,
+        uploadid,
+        fileid,
+        url
+    };
+}
+
+/**
+ * Fetch data from URL with exponential backoff
+ * @param {string} url - URL to fetch from
+ * @param {number} maxRetries - Maximum number of retry attempts
+ * @param {number} baseDelay - Initial delay in milliseconds
+ * @param {number} maxDelay - Maximum delay in milliseconds
+ * @param {string} correlationId - Correlation ID for logging
+ * @returns {Promise<Uint8Array>} Fetched data as bytes
+ */
+async function fetchWithBackoff(url, maxRetries, baseDelay, maxDelay, correlationId) {
+    let delay = baseDelay;
+    
+    for (let attempt = 1; attempt <= maxRetries; attempt++) {
+        try {
+            const response = await fetch(url);
+            
+            if (response.status === 200) {
+                logTrace(correlationId, `Successfully fetched data from ${url} on attempt ${attempt}`);
+                const arrayBuffer = await response.arrayBuffer();
+                return new Uint8Array(arrayBuffer);
+            } else {
+                throw new Error(`Failed to fetch: ${response.status}`);
+            }
+        } catch (e) {
+            logTrace(correlationId, `Attempt ${attempt} failed: ${e.constructor.name}`);
+            
+            if (attempt < maxRetries) {
+                await new Promise(resolve => setTimeout(resolve, delay));
+                delay = Math.min(delay * 2, maxDelay);
+            }
+        }
+    }
+    
+    throw new Error(`Failed to fetch data after ${maxRetries} attempts`);
+}
+
+// ---------------------------------------------- NATS Client ---------------------------------------------- //
+
+/**
+ * NATS client wrapper for connection management
+ */
+class NATSClient {
+    /**
+     * Create a new NATS client
+     * @param {string} url - NATS server URL
+     */
+    constructor(url) {
+        this.url = url;
+        this.connection = null;
+    }
+
+    /**
+     * Connect to NATS server
+     * @returns {Promise<NATS.Connection>}
+     */
+    async connect() {
+        this.connection = await nats.connect({ servers: this.url });
+        return this.connection;
+    }
+
+    /**
+     * Publish message to NATS subject
+     * @param {string} subject - NATS subject to publish to
+     * @param {string} message - Message to publish
+     * @param {string} correlationId - Correlation ID for logging
+     */
+    async publish(subject, message, correlationId) {
+        if (!this.connection) {
+            await this.connect();
+        }
+        await this.connection.publish(subject, message);
+        logTrace(correlationId, `Message published to ${subject}`);
+    }
+
+    /**
+     * Close the NATS connection
+     */
+    async close() {
+        if (this.connection) {
+            this.connection.close();
+        }
+    }
+}
+
+// ---------------------------------------------- Core Functions ---------------------------------------------- //
+
+/**
+ * Publish message to NATS
+ * @param {string|NATSClient|NATS.Connection} brokerUrlOrClient - NATS URL, client, or connection
+ * @param {string} subject - NATS subject to publish to
+ * @param {string} message - JSON message to publish
+ * @param {string} correlationId - Correlation ID for tracing
+ */
+async function publishMessage(brokerUrlOrClient, subject, message, correlationId) {
+    let conn;
+    
+    if (brokerUrlOrClient instanceof NATSClient) {
+        conn = brokerUrlOrClient;
+    } else if (brokerUrlOrClient instanceof nats.Connection) {
+        // Create a wrapper for direct connection
+        conn = {
+            async publish(subj, msg) {
+                await brokerUrlOrClient.publish(subj, msg);
+            },
+            async close() {
+                await brokerUrlOrClient.close();
+            }
+        };
+    } else {
+        // String URL - create new client
+        const client = new NATSClient(brokerUrlOrClient);
+        conn = client;
+    }
+    
+    await conn.publish(subject, message, correlationId);
+    
+    if (conn instanceof NATSClient) {
+        await conn.close();
+    }
+}
+
+/**
+ * Build message envelope from payloads and metadata
+ * @param {string} subject - NATS subject
+ * @param {Array} payloads - Array of payload objects
+ * @param {Object} options - Envelope metadata options
+ * @returns {Object} Envelope object
+ */
+function buildEnvelope(subject, payloads, options) {
+    return {
+        correlation_id: options.correlation_id,
+        msg_id: options.msg_id,
+        timestamp: new Date().toISOString(),
+        send_to: subject,
+        msg_purpose: options.msg_purpose,
+        sender_name: options.sender_name,
+        sender_id: options.sender_id,
+        receiver_name: options.receiver_name,
+        receiver_id: options.receiver_id,
+        reply_to: options.reply_to,
+        reply_to_msg_id: options.reply_to_msg_id,
+        broker_url: options.broker_url,
+        metadata: options.metadata || {},
+        payloads: payloads
+    };
+}
+
+/**
+ * Build payload object from serialized data
+ * @param {string} dataname - Name of the payload
+ * @param {string} payloadType - Type of the payload
+ * @param {Buffer} payloadBytes - Serialized payload bytes
+ * @param {string} transport - Transport type ("direct" or "link")
+ * @param {string} data - Data (base64 for direct, URL for link)
+ * @returns {Object} Payload object
+ */
+function buildPayload(dataname, payloadType, payloadBytes, transport, data) {
+    return {
+        id: uuidv4(),
+        dataname,
+        payload_type: payloadType,
+        transport,
+        encoding: transport === 'direct' ? 'base64' : 'none',
+        size: payloadBytes.byteLength,
+        data,
+        metadata: transport === 'direct' ? { payload_bytes: payloadBytes.byteLength } : {}
+    };
+}
+
+/**
+ * Send data via NATS with automatic transport selection
+ * 
+ * This function intelligently routes data delivery based on payload size.
+ * If the serialized payload is smaller than size_threshold, it encodes the data as Base64
+ * and publishes directly over NATS. Otherwise, it uploads the data to a fileserver
+ * and publishes only the download URL over NATS.
+ * 
+ * @param {string} subject - NATS subject to publish the message to
+ * @param {Array} data - List of [dataname, data, type] tuples to send
+ * @param {Object} options - Optional configuration
+ * @param {string} [options.broker_url=DEFAULT_BROKER_URL] - URL of the NATS server
+ * @param {string} [options.fileserver_url=DEFAULT_FILESERVER_URL] - URL of the HTTP file server
+ * @param {Function} [options.fileserver_upload_handler=plikOneshotUpload] - Function to handle fileserver uploads
+ * @param {number} [options.size_threshold=DEFAULT_SIZE_THRESHOLD] - Threshold separating direct vs link transport
+ * @param {string} [options.correlation_id=uuidv4()] - Correlation ID for tracing
+ * @param {string} [options.msg_purpose="chat"] - Purpose of the message
+ * @param {string} [options.sender_name="NATSBridge"] - Name of the sender
+ * @param {string} [options.receiver_name=""] - Name of the receiver (empty means broadcast)
+ * @param {string} [options.receiver_id=""] - UUID of the receiver (empty means broadcast)
+ * @param {string} [options.reply_to=""] - Topic to reply to
+ * @param {string} [options.reply_to_msg_id=""] - Message ID this message is replying to
+ * @param {boolean} [options.is_publish=true] - Whether to automatically publish the message
+ * @param {NATSClient|NATS.Connection} [options.nats_connection=null] - Pre-existing NATS connection
+ * @param {string} [options.msg_id=uuidv4()] - Message ID
+ * @param {string} [options.sender_id=uuidv4()] - Sender ID
+ * @returns {Promise<[Object, string]>} Tuple of [env, env_json_str]
+ * 
+ * @example
+ * // Send a single payload
+ * const [env, envJsonStr] = await smartsend(
+ *     "/test",
+ *     [["dataname1", data1, "dictionary"]],
+ *     { broker_url: "nats://localhost:4222" }
+ * );
+ * 
+ * // Send multiple payloads
+ * const [env, envJsonStr] = await smartsend(
+ *     "/test",
+ *     [
+ *         ["dataname1", data1, "dictionary"],
+ *         ["dataname2", data2, "table"]
+ *     ],
+ *     { broker_url: "nats://localhost:4222" }
+ * );
+ * 
+ * // Send with pre-existing connection
+ * const client = await NATSBridge.NATSClient.connect("nats://localhost:4222");
+ * const [env, envJsonStr] = await smartsend(
+ *     "/test",
+ *     [["data", myData, "text"]],
+ *     { nats_connection: client }
+ * );
+ */
+async function smartsend(subject, data, options = {}) {
+    const {
+        broker_url = DEFAULT_BROKER_URL,
+        fileserver_url = DEFAULT_FILESERVER_URL,
+        fileserver_upload_handler = plikOneshotUpload,
+        size_threshold = DEFAULT_SIZE_THRESHOLD,
+        correlation_id = uuidv4(),
+        msg_purpose = 'chat',
+        sender_name = 'NATSBridge',
+        receiver_name = '',
+        receiver_id = '',
+        reply_to = '',
+        reply_to_msg_id = '',
+        is_publish = true,
+        nats_connection = null,
+        msg_id = uuidv4(),
+        sender_id = uuidv4()
+    } = options;
+
+    logTrace(correlation_id, `Starting smartsend for subject: ${subject}`);
+
+    // Process payloads
+    const payloads = [];
+    for (const [dataname, payloadData, payloadType] of data) {
+        const payloadBytes = await serializeData(payloadData, payloadType);
+        const payloadSize = payloadBytes.byteLength;
+
+        logTrace(correlation_id, `Serialized payload '${dataname}' (type: ${payloadType}) size: ${payloadSize} bytes`);
+
+        if (payloadSize < size_threshold) {
+            // Direct path
+            const payloadB64 = bufferToBase64(payloadBytes);
+            logTrace(correlation_id, `Using direct transport for ${payloadSize} bytes`);
+
+            const payload = buildPayload(dataname, payloadType, payloadBytes, 'direct', payloadB64);
+            payloads.push(payload);
+        } else {
+            // Link path
+            logTrace(correlation_id, `Using link transport, uploading to fileserver`);
+
+            const response = await fileserver_upload_handler(fileserver_url, dataname, payloadBytes);
+
+            if (response.status !== 200) {
+                throw new Error(`Failed to upload data to fileserver: ${response.status}`);
+            }
+
+            logTrace(correlation_id, `Uploaded to URL: ${response.url}`);
+
+            const payload = buildPayload(dataname, payloadType, payloadBytes, 'link', response.url);
+            payloads.push(payload);
+        }
+    }
+
+    // Build envelope
+    const env = buildEnvelope(subject, payloads, {
+        correlation_id,
+        msg_id,
+        msg_purpose,
+        sender_name,
+        sender_id,
+        receiver_name,
+        receiver_id,
+        reply_to,
+        reply_to_msg_id,
+        broker_url
+    });
+
+    const env_json_str = JSON.stringify(env);
+
+    if (is_publish) {
+        if (nats_connection) {
+            await publishMessage(nats_connection, subject, env_json_str, correlation_id);
+        } else {
+            await publishMessage(broker_url, subject, env_json_str, correlation_id);
+        }
+    }
+
+    return [env, env_json_str];
+}
+
+/**
+ * Receive and process NATS message
+ * 
+ * This function processes incoming NATS messages, handling both direct transport
+ * (base64 decoded payloads) and link transport (URL-based payloads).
+ * It deserializes the data based on the transport type and returns the result.
+ * 
+ * @param {Object} msg - NATS message object with payload property
+ * @param {Object} options - Optional configuration
+ * @param {Function} [options.fileserver_download_handler=fetchWithBackoff] - Function to handle fileserver downloads
+ * @param {number} [options.max_retries=5] - Maximum retry attempts for fetching URL
+ * @param {number} [options.base_delay=100] - Initial delay for exponential backoff in ms
+ * @param {number} [options.max_delay=5000] - Maximum delay for exponential backoff in ms
+ * @returns {Promise<Object>} Envelope object with processed payloads
+ * 
+ * @example
+ * // Receive and process message
+ * const env = await smartreceive(msg, {
+ *     fileserver_download_handler: fetchWithBackoff,
+ *     max_retries: 5,
+ *     base_delay: 100,
+ *     max_delay: 5000
+ * });
+ * // env.payloads is an Array of [dataname, data, type] arrays
+ * for (const [dataname, data, type] of env.payloads) {
+ *     console.log(`${dataname}: ${data} (type: ${type})`);
+ * }
+ */
+async function smartreceive(msg, options = {}) {
+    const {
+        fileserver_download_handler = fetchWithBackoff,
+        max_retries = 5,
+        base_delay = 100,
+        max_delay = 5000
+    } = options;
+
+    // Parse the JSON envelope
+    const payload = typeof msg.payload === 'string' ? msg.payload : Buffer.from(msg.payload).toString('utf8');
+    const envJsonObj = JSON.parse(payload);
+    logTrace(envJsonObj.correlation_id, 'Processing received message');
+
+    // Process all payloads in the envelope
+    const payloadsList = [];
+    const numPayloads = envJsonObj.payloads.length;
+
+    for (let i = 0; i < numPayloads; i++) {
+        const payloadObj = envJsonObj.payloads[i];
+        const transport = payloadObj.transport;
+        const dataname = payloadObj.dataname;
+
+        if (transport === 'direct') {
+            logTrace(envJsonObj.correlation_id, `Direct transport - decoding payload '${dataname}'`);
+
+            // Extract base64 payload from the payload
+            const payloadB64 = payloadObj.data;
+
+            // Decode Base64 payload
+            const payloadBytes = Buffer.from(payloadB64, 'base64');
+
+            // Deserialize based on type
+            const dataType = payloadObj.payload_type;
+            const data = await deserializeData(payloadBytes, dataType, envJsonObj.correlation_id);
+
+            payloadsList.push([dataname, data, dataType]);
+        } else if (transport === 'link') {
+            // Extract download URL from the payload
+            const url = payloadObj.data;
+            logTrace(envJsonObj.correlation_id, `Link transport - fetching '${dataname}' from URL: ${url}`);
+
+            // Fetch with exponential backoff using the download handler
+            const downloadedData = await fileserver_download_handler(
+                url,
+                max_retries,
+                base_delay,
+                max_delay,
+                envJsonObj.correlation_id
+            );
+
+            // Deserialize based on type
+            const dataType = payloadObj.payload_type;
+            const data = await deserializeData(downloadedData, dataType, envJsonObj.correlation_id);
+
+            payloadsList.push([dataname, data, dataType]);
+        } else {
+            throw new Error(`Unknown transport type for payload '${dataname}': ${transport}`);
+        }
+    }
+
+    envJsonObj.payloads = payloadsList;
+    return envJsonObj;
+}
+
+// ---------------------------------------------- Module Exports ---------------------------------------------- //
+
+const NATSBridge = {
+    /**
+     * NATS client class for connection management
+     */
+    NATSClient,
+
+    /**
+     * Send data via NATS with automatic transport selection
+     */
+    smartsend,
+
+    /**
+     * Receive and process NATS message
+     */
+    smartreceive,
+
+    /**
+     * Upload data to plik server in one-shot mode
+     */
+    plikOneshotUpload,
+
+    /**
+     * Fetch data from URL with exponential backoff
+     */
+    fetchWithBackoff,
+
+    /**
+     * Default constants
+     */
+    DEFAULT_SIZE_THRESHOLD,
+    DEFAULT_BROKER_URL,
+    DEFAULT_FILESERVER_URL
+};
+
+module.exports = NATSBridge;

src/natsbridge.py

@@ -0,0 +1,815 @@
+"""
+NATSBridge - Cross-Platform Bi-Directional Data Bridge
+Python Desktop Implementation
+
+This module provides functionality for sending and receiving data across network boundaries
+using NATS as the message bus, with support for both direct payload transport and
+URL-based transport for larger payloads.
+
+@package natsbridge
+"""
+
+import asyncio
+import base64
+import json
+import uuid
+from datetime import datetime
+from typing import Any, Callable, Dict, List, Tuple, Union
+import aiohttp
+
+try:
+    import pyarrow as arrow
+    import pyarrow.ipc as ipc
+    ARROW_AVAILABLE = True
+except ImportError:
+    ARROW_AVAILABLE = False
+
+try:
+    import nats
+    from nats.aio.client import Client as NATSClient
+    NATS_AVAILABLE = True
+except ImportError:
+    NATS_AVAILABLE = False
+
+# ---------------------------------------------- Constants ---------------------------------------------- #
+
+"""
+Default size threshold for switching from direct to link transport (1MB)
+"""
+DEFAULT_SIZE_THRESHOLD = 1_000_000
+
+"""
+Default NATS server URL
+"""
+DEFAULT_BROKER_URL = "nats://localhost:4222"
+
+"""
+Default HTTP file server URL for link transport
+"""
+DEFAULT_FILESERVER_URL = "http://localhost:8080"
+
+
+# ---------------------------------------------- Utility Functions ---------------------------------------------- #
+
+def log_trace(correlation_id: str, message: str) -> None:
+    """
+    Log a trace message with correlation ID and timestamp.
+    
+    Args:
+        correlation_id: Correlation ID for tracing
+        message: Message content to log
+    """
+    timestamp = datetime.utcnow().isoformat() + 'Z'
+    print(f"[{timestamp}] [Correlation: {correlation_id}] {message}")
+
+
+# ---------------------------------------------- Serialization Functions ---------------------------------------------- #
+
+def _serialize_data(data: Any, payload_type: str) -> bytes:
+    """
+    Serialize data according to specified format.
+    
+    Args:
+        data: Data to serialize (string for "text", JSON-serializable for "dictionary",
+              table-like for "table", binary for "image", "audio", "video", "binary")
+        payload_type: Target format: "text", "dictionary", "table", "image", "audio", "video", "binary"
+    
+    Returns:
+        Binary representation of the serialized data
+    
+    Raises:
+        Error: If payload_type is not one of the supported types
+        Error: If payload_type is "image", "audio", or "video" but data is not bytes
+        Error: If payload_type is "table" but data is not a pandas DataFrame or pyarrow Table
+    """
+    if payload_type == 'text':
+        if isinstance(data, str):
+            return data.encode('utf-8')
+        else:
+            raise ValueError('Text data must be a string')
+    elif payload_type == 'dictionary':
+        json_str = json.dumps(data)
+        return json_str.encode('utf-8')
+    elif payload_type == 'table':
+        if not ARROW_AVAILABLE:
+            raise RuntimeError('pyarrow not available for table serialization')
+        
+        import io
+        buf = io.BytesIO()
+        
+        import pandas as pd
+        if isinstance(data, pd.DataFrame):
+            table = arrow.Table.from_pandas(data)
+            sink = ipc.new_file(buf, table.schema)
+            ipc.write_table(table, sink)
+            sink.close()
+            return buf.getvalue()
+        elif isinstance(data, arrow.Table):
+            sink = ipc.new_file(buf, data.schema)
+            ipc.write_table(data, sink)
+            sink.close()
+            return buf.getvalue()
+        else:
+            raise ValueError('Table data must be a pandas DataFrame or pyarrow Table')
+    elif payload_type == 'image':
+        if isinstance(data, (bytes, bytearray)):
+            return bytes(data)
+        else:
+            raise ValueError('Image data must be bytes')
+    elif payload_type == 'audio':
+        if isinstance(data, (bytes, bytearray)):
+            return bytes(data)
+        else:
+            raise ValueError('Audio data must be bytes')
+    elif payload_type == 'video':
+        if isinstance(data, (bytes, bytearray)):
+            return bytes(data)
+        else:
+            raise ValueError('Video data must be bytes')
+    elif payload_type == 'binary':
+        if isinstance(data, (bytes, bytearray)):
+            return bytes(data)
+        else:
+            raise ValueError('Binary data must be bytes')
+    else:
+        raise ValueError(f'Unknown payload_type: {payload_type}')
+
+
+def _deserialize_data(data: bytes, payload_type: str, correlation_id: str) -> Any:
+    """
+    Deserialize bytes to data based on type.
+    
+    Args:
+        data: Serialized data as bytes
+        payload_type: Data type ("text", "dictionary", "table", "image", "audio", "video", "binary")
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        Deserialized data (String for "text", DataFrame for "table", JSON data for "dictionary",
+        bytes for "image", "audio", "video", "binary")
+    
+    Raises:
+        Error: If payload_type is not one of the supported types
+    """
+    if payload_type == 'text':
+        return data.decode('utf-8')
+    elif payload_type == 'dictionary':
+        json_str = data.decode('utf-8')
+        return json.loads(json_str)
+    elif payload_type == 'table':
+        if not ARROW_AVAILABLE:
+            raise RuntimeError('pyarrow not available for table deserialization')
+        
+        import io
+        buf = io.BytesIO(data)
+        reader = ipc.open_file(buf)
+        return reader.read_all().to_pandas()
+    elif payload_type == 'image':
+        return data
+    elif payload_type == 'audio':
+        return data
+    elif payload_type == 'video':
+        return data
+    elif payload_type == 'binary':
+        return data
+    else:
+        raise ValueError(f'Unknown payload_type: {payload_type}')
+
+
+# ---------------------------------------------- File Server Handlers ---------------------------------------------- #
+
+async def plik_oneshot_upload(
+    file_server_url: str,
+    dataname: str,
+    data: bytes
+) -> Dict[str, Any]:
+    """
+    Upload data to plik server in one-shot mode.
+    
+    This function uploads a raw byte array to a plik server in one-shot mode (no upload session).
+    It first creates a one-shot upload session by sending a POST request with {"OneShot": true},
+    retrieves an upload ID and token, then uploads the file data as multipart form data using the token.
+    
+    Args:
+        file_server_url: Base URL of the plik server (e.g., "http://localhost:8080")
+        dataname: Name of the file being uploaded
+        data: Raw byte data of the file content
+    
+    Returns:
+        Dict with keys:
+            - "status": HTTP server response status
+            - "uploadid": ID of the one-shot upload session
+            - "fileid": ID of the uploaded file within the session
+            - "url": Full URL to download the uploaded file
+    
+    Example:
+        >>> fileserver_url = "http://localhost:8080"
+        >>> dataname = "test.txt"
+        >>> data = b"hello world"
+        >>> result = await plik_oneshot_upload(file_server_url, dataname, data)
+        >>> result["status"], result["uploadid"], result["fileid"], result["url"]
+    """
+    async with aiohttp.ClientSession() as session:
+        # Get upload id
+        url_getUploadID = f"{file_server_url}/upload"
+        headers = {'Content-Type': 'application/json'}
+        body = json.dumps({"OneShot": True})
+        
+        async with session.post(url_getUploadID, headers=headers, data=body) as response:
+            response_json = await response.json()
+            uploadid = response_json['id']
+            uploadtoken = response_json['uploadToken']
+
+        # Upload file
+        url_upload = f"{file_server_url}/file/{uploadid}"
+        headers = {'X-UploadToken': uploadtoken}
+        
+        form = aiohttp.FormData()
+        form.add_field('file', data, filename=dataname, content_type='application/octet-stream')
+        
+        async with session.post(url_upload, headers=headers, data=form) as upload_response:
+            upload_json = await upload_response.json()
+            fileid = upload_json['id']
+
+    url = f"{file_server_url}/file/{uploadid}/{fileid}/{dataname}"
+
+    return {
+        'status': upload_response.status,
+        'uploadid': uploadid,
+        'fileid': fileid,
+        'url': url
+    }
+
+
+async def fetch_with_backoff(
+    url: str,
+    max_retries: int,
+    base_delay: int,
+    max_delay: int,
+    correlation_id: str
+) -> bytes:
+    """
+    Fetch data from URL with exponential backoff.
+    
+    This internal function retrieves data from a URL with retry logic using
+    exponential backoff to handle transient failures.
+    
+    Args:
+        url: URL to fetch from
+        max_retries: Maximum number of retry attempts
+        base_delay: Initial delay in milliseconds
+        max_delay: Maximum delay in milliseconds
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        Fetched data as bytes
+    
+    Raises:
+        Error: If all retry attempts fail
+    
+    Example:
+        >>> data = await fetch_with_backoff("http://example.com/file.zip", 5, 100, 5000, "correlation123")
+    """
+    delay = base_delay
+    
+    for attempt in range(1, max_retries + 1):
+        try:
+            async with aiohttp.ClientSession() as session:
+                async with session.get(url) as response:
+                    if response.status == 200:
+                        log_trace(correlation_id, f"Successfully fetched data from {url} on attempt {attempt}")
+                        return await response.read()
+                    else:
+                        raise Exception(f"Failed to fetch: {response.status}")
+        except Exception as e:
+            log_trace(correlation_id, f"Attempt {attempt} failed: {type(e).__name__}")
+            
+            if attempt < max_retries:
+                await asyncio.sleep(delay / 1000.0)
+                delay = min(delay * 2, max_delay)
+    
+    raise Exception(f"Failed to fetch data after {max_retries} attempts")
+
+
+# ---------------------------------------------- NATS Client ---------------------------------------------- #
+
+class NATSClient:
+    """NATS client wrapper for connection management."""
+    
+    def __init__(self, url: str = DEFAULT_BROKER_URL):
+        """
+        Create a new NATS client.
+        
+        Args:
+            url: NATS server URL
+        """
+        self.url = url
+        self._client: NATSClient = None
+    
+    async def connect(self) -> NATSClient:
+        """
+        Connect to NATS server.
+        
+        Returns:
+            NATS client instance
+        """
+        if NATS_AVAILABLE:
+            self._client = nats.connect(self.url)
+            await self._client
+        else:
+            raise Error('nats-py not available')
+        return self._client
+    
+    async def publish(self, subject: str, message: str, correlation_id: str = "") -> None:
+        """
+        Publish message to NATS subject.
+        
+        Args:
+            subject: NATS subject to publish to
+            message: Message to publish
+            correlation_id: Correlation ID for logging
+        """
+        if self._client:
+            await self._client.publish(subject, message)
+            if correlation_id:
+                log_trace(correlation_id, f"Message published to {subject}")
+    
+    async def close(self) -> None:
+        """Close the NATS connection."""
+        if self._client:
+            await self._client.drain()
+            await self._client.close()
+
+
+# ---------------------------------------------- Core Functions ---------------------------------------------- #
+
+def _build_envelope(
+    subject: str,
+    payloads: List[Dict[str, Any]],
+    options: Dict[str, Any]
+) -> Dict[str, Any]:
+    """
+    Build message envelope from payloads and metadata.
+    
+    Args:
+        subject: NATS subject
+        payloads: Array of payload objects
+        options: Envelope metadata options
+    
+    Returns:
+        Envelope object
+    """
+    return {
+        'correlation_id': options['correlation_id'],
+        'msg_id': options['msg_id'],
+        'timestamp': datetime.utcnow().isoformat() + 'Z',
+        'send_to': subject,
+        'msg_purpose': options['msg_purpose'],
+        'sender_name': options['sender_name'],
+        'sender_id': options['sender_id'],
+        'receiver_name': options['receiver_name'],
+        'receiver_id': options['receiver_id'],
+        'reply_to': options['reply_to'],
+        'reply_to_msg_id': options['reply_to_msg_id'],
+        'broker_url': options['broker_url'],
+        'metadata': options.get('metadata', {}),
+        'payloads': payloads
+    }
+
+
+def _build_payload(
+    dataname: str,
+    payload_type: str,
+    payload_bytes: bytes,
+    transport: str,
+    data: Union[str, bytes]
+) -> Dict[str, Any]:
+    """
+    Build payload object from serialized data.
+    
+    Args:
+        dataname: Name of the payload
+        payload_type: Type of the payload
+        payload_bytes: Serialized payload bytes
+        transport: Transport type ("direct" or "link")
+        data: Data (base64 for direct, URL for link)
+    
+    Returns:
+        Payload object
+    """
+    return {
+        'id': str(uuid.uuid4()),
+        'dataname': dataname,
+        'payload_type': payload_type,
+        'transport': transport,
+        'encoding': 'base64' if transport == 'direct' else 'none',
+        'size': len(payload_bytes),
+        'data': data,
+        'metadata': {'payload_bytes': len(payload_bytes)} if transport == 'direct' else {}
+    }
+
+
+async def publish_message(
+    broker_url_or_client: Union[str, NATSClient, Any],
+    subject: str,
+    message: str,
+    correlation_id: str
+) -> None:
+    """
+    Publish message to NATS.
+    
+    Args:
+        broker_url_or_client: NATS URL, client, or connection
+        subject: NATS subject to publish to
+        message: JSON message to publish
+        correlation_id: Correlation ID for tracing
+    """
+    if isinstance(broker_url_or_client, NATSClient):
+        client = broker_url_or_client
+    elif NATS_AVAILABLE and hasattr(broker_url_or_client, 'publish'):
+        # Direct NATS client connection
+        await broker_url_or_client.publish(subject, message)
+        log_trace(correlation_id, f"Message published to {subject}")
+        return
+    else:
+        # String URL - create new client
+        client = NATSClient(broker_url_or_client)
+        await client.connect()
+    
+    await client.publish(subject, message, correlation_id)
+    
+    if isinstance(broker_url_or_client, NATSClient):
+        await broker_url_or_client.close()
+    elif not (NATS_AVAILABLE and hasattr(broker_url_or_client, 'publish')):
+        await client.close()
+
+
+async def smartsend(
+    subject: str,
+    data: List[Tuple[str, Any, str]],
+    broker_url: str = DEFAULT_BROKER_URL,
+    fileserver_url: str = DEFAULT_FILESERVER_URL,
+    fileserver_upload_handler: Callable = plik_oneshot_upload,
+    size_threshold: int = DEFAULT_SIZE_THRESHOLD,
+    correlation_id: str = None,
+    msg_purpose: str = "chat",
+    sender_name: str = "NATSBridge",
+    receiver_name: str = "",
+    receiver_id: str = "",
+    reply_to: str = "",
+    reply_to_msg_id: str = "",
+    is_publish: bool = True,
+    nats_connection: Any = None,
+    msg_id: str = None,
+    sender_id: str = None
+) -> Tuple[Dict, str]:
+    """
+    Send data via NATS with automatic transport selection.
+    
+    This function intelligently routes data delivery based on payload size.
+    If the serialized payload is smaller than size_threshold, it encodes the data as Base64
+    and publishes directly over NATS. Otherwise, it uploads the data to a fileserver
+    and publishes only the download URL over NATS.
+    
+    Args:
+        subject: NATS subject to publish the message to
+        data: List of (dataname, data, type) tuples to send
+            - dataname: Name of the payload
+            - data: The actual data to send
+            - type: Payload type: "text", "dictionary", "table", "image", "audio", "video", "binary"
+        broker_url: URL of the NATS server
+        fileserver_url: URL of the HTTP file server for large payloads
+        fileserver_upload_handler: Function to handle fileserver uploads (must return Dict with "status",
+                                   "uploadid", "fileid", "url" keys)
+        size_threshold: Threshold in bytes separating direct vs link transport
+        correlation_id: Correlation ID for tracing (auto-generated UUID if not provided)
+        msg_purpose: Purpose of the message: "ACK", "NACK", "updateStatus", "shutdown", "chat", etc.
+        sender_name: Name of the sender
+        receiver_name: Name of the receiver (empty string means broadcast)
+        receiver_id: UUID of the receiver (empty string means broadcast)
+        reply_to: Topic to reply to (empty string if no reply expected)
+        reply_to_msg_id: Message ID this message is replying to
+        is_publish: Whether to automatically publish the message to NATS
+        nats_connection: Pre-existing NATS connection (if provided, uses this connection instead of
+                        creating a new one; saves connection establishment overhead)
+        msg_id: Message ID (auto-generated UUID if not provided)
+        sender_id: Sender ID (auto-generated UUID if not provided)
+    
+    Returns:
+        Tuple of (env, env_json_str) where:
+            - env: Dict containing all metadata and payloads
+            - env_json_str: JSON string for publishing to NATS
+    
+    Example:
+        >>> # Send a single payload (still wrapped in a list)
+        >>> data = {"key": "value"}
+        >>> env, env_json_str = await smartsend(
+        ...     "my.subject",
+        ...     [("dataname1", data, "dictionary")],
+        ...     broker_url="nats://localhost:4222"
+        ... )
+        >>>
+        >>> # Send multiple payloads with different types
+        >>> data1 = {"key1": "value1"}
+        >>> data2 = [1, 2, 3, 4, 5]
+        >>> env, env_json_str = await smartsend(
+        ...     "my.subject",
+        ...     [("dataname1", data1, "dictionary"), ("dataname2", data2, "table")]
+        ... )
+        >>>
+        >>> # Send a large array using fileserver upload
+        >>> data = list(range(10_000_000))  # ~80 MB
+        >>> env, env_json_str = await smartsend(
+        ...     "large.data",
+        ...     [("large_table", data, "table")]
+        ... )
+        >>>
+        >>> # Mixed content (e.g., chat with text and image)
+        >>> env, env_json_str = await smartsend(
+        ...     "chat.subject",
+        ...     [
+        ...         ("message_text", "Hello!", "text"),
+        ...         ("user_image", image_data, "image"),
+        ...         ("audio_clip", audio_data, "audio")
+        ...     ]
+        ... )
+        >>>
+        >>> # Publish the JSON string directly using NATS request-reply pattern
+        >>> # reply = await nats.request(broker_url, subject, env_json_str, reply_to=reply_to_topic)
+    """
+    if correlation_id is None:
+        correlation_id = str(uuid.uuid4())
+    if msg_id is None:
+        msg_id = str(uuid.uuid4())
+    if sender_id is None:
+        sender_id = str(uuid.uuid4())
+    
+    log_trace(correlation_id, f"Starting smartsend for subject: {subject}")
+    
+    # Process payloads
+    payloads = []
+    for dataname, payload_data, payload_type in data:
+        payload_bytes = _serialize_data(payload_data, payload_type)
+        payload_size = len(payload_bytes)
+        
+        log_trace(correlation_id, f"Serialized payload '{dataname}' (type: {payload_type}) size: {payload_size} bytes")
+        
+        if payload_size < size_threshold:
+            # Direct path
+            payload_b64 = base64.b64encode(payload_bytes).decode('utf-8')
+            log_trace(correlation_id, f"Using direct transport for {payload_size} bytes")
+            
+            payload = _build_payload(dataname, payload_type, payload_bytes, 'direct', payload_b64)
+            payloads.append(payload)
+        else:
+            # Link path
+            log_trace(correlation_id, "Using link transport, uploading to fileserver")
+            
+            response = await fileserver_upload_handler(fileserver_url, dataname, payload_bytes)
+            
+            if response['status'] != 200:
+                raise Exception(f"Failed to upload data to fileserver: {response['status']}")
+            
+            log_trace(correlation_id, f"Uploaded to URL: {response['url']}")
+            
+            payload = _build_payload(dataname, payload_type, payload_bytes, 'link', response['url'])
+            payloads.append(payload)
+    
+    # Build envelope
+    env = _build_envelope(subject, payloads, {
+        'correlation_id': correlation_id,
+        'msg_id': msg_id,
+        'msg_purpose': msg_purpose,
+        'sender_name': sender_name,
+        'sender_id': sender_id,
+        'receiver_name': receiver_name,
+        'receiver_id': receiver_id,
+        'reply_to': reply_to,
+        'reply_to_msg_id': reply_to_msg_id,
+        'broker_url': broker_url
+    })
+    
+    env_json_str = json.dumps(env)
+    
+    if is_publish:
+        if nats_connection:
+            await publish_message(nats_connection, subject, env_json_str, correlation_id)
+        else:
+            await publish_message(broker_url, subject, env_json_str, correlation_id)
+    
+    return env, env_json_str
+
+
+async def smartreceive(
+    msg: Any,
+    fileserver_download_handler: Callable = fetch_with_backoff,
+    max_retries: int = 5,
+    base_delay: int = 100,
+    max_delay: int = 5000
+) -> Dict[str, Any]:
+    """
+    Receive and process NATS messages.
+    
+    This function processes incoming NATS messages, handling both direct transport
+    (base64 decoded payloads) and link transport (URL-based payloads).
+    It deserializes the data based on the transport type and returns the result.
+    
+    Args:
+        msg: NATS message to process
+        fileserver_download_handler: Function to handle downloading data from file server URLs
+        max_retries: Maximum retry attempts for fetching URL
+        base_delay: Initial delay for exponential backoff in ms
+        max_delay: Maximum delay for exponential backoff in ms
+    
+    Returns:
+        Dict with envelope metadata and payloads field containing List[Tuple[str, Any, str]]
+    
+    Example:
+        >>> # Receive and process message
+        >>> env = await smartreceive(msg, fileserver_download_handler=fetch_with_backoff)
+        >>> # env is a Dict with "payloads" key containing List[Tuple[str, Any, str]]
+        >>> # Access payloads: for dataname, data, type_ in env["payloads"]
+        >>> for dataname, data, type_ in env["payloads"]:
+        >>>     print(f"{dataname}: {data} (type: {type_})")
+    """
+    # Parse the JSON envelope
+    if isinstance(msg, dict):
+        # Already parsed
+        env_json_obj = msg
+    elif hasattr(msg, 'payload'):
+        # NATS message object
+        payload = msg.payload if isinstance(msg.payload, str) else msg.payload.decode('utf-8')
+        env_json_obj = json.loads(payload)
+    else:
+        # Assume it's already a JSON string or dict
+        env_json_obj = json.loads(msg) if isinstance(msg, str) else msg
+    
+    log_trace(env_json_obj['correlation_id'], "Processing received message")
+    
+    # Process all payloads in the envelope
+    payloads_list = []
+    num_payloads = len(env_json_obj['payloads'])
+    
+    for i in range(num_payloads):
+        payload_obj = env_json_obj['payloads'][i]
+        transport = payload_obj['transport']
+        dataname = payload_obj['dataname']
+        
+        if transport == 'direct':
+            log_trace(env_json_obj['correlation_id'], f"Direct transport - decoding payload '{dataname}'")
+            
+            # Extract base64 payload from the payload
+            payload_b64 = payload_obj['data']
+            
+            # Decode Base64 payload
+            payload_bytes = base64.b64decode(payload_b64)
+            
+            # Deserialize based on type
+            data_type = payload_obj['payload_type']
+            data = _deserialize_data(payload_bytes, data_type, env_json_obj['correlation_id'])
+            
+            payloads_list.append((dataname, data, data_type))
+        elif transport == 'link':
+            # Extract download URL from the payload
+            url = payload_obj['data']
+            log_trace(env_json_obj['correlation_id'], f"Link transport - fetching '{dataname}' from URL: {url}")
+            
+            # Fetch with exponential backoff using the download handler
+            downloaded_data = await fileserver_download_handler(
+                url,
+                max_retries,
+                base_delay,
+                max_delay,
+                env_json_obj['correlation_id']
+            )
+            
+            # Deserialize based on type
+            data_type = payload_obj['payload_type']
+            data = _deserialize_data(downloaded_data, data_type, env_json_obj['correlation_id'])
+            
+            payloads_list.append((dataname, data, data_type))
+        else:
+            raise Exception(f"Unknown transport type for payload '{dataname}': {transport}")
+    
+    env_json_obj['payloads'] = payloads_list
+    return env_json_obj
+
+
+# ---------------------------------------------- Module Exports ---------------------------------------------- #
+
+class NATSBridge:
+    """
+    Cross-platform NATS bridge implementation.
+    
+    This class provides a convenient interface for NATSBridge functionality,
+    encapsulating the main functions and providing a class-based API.
+    """
+    
+    DEFAULT_SIZE_THRESHOLD = DEFAULT_SIZE_THRESHOLD
+    DEFAULT_BROKER_URL = DEFAULT_BROKER_URL
+    DEFAULT_FILESERVER_URL = DEFAULT_FILESERVER_URL
+    
+    def __init__(self, broker_url: str = None, fileserver_url: str = None):
+        """
+        Initialize NATSBridge.
+        
+        Args:
+            broker_url: NATS server URL (defaults to DEFAULT_BROKER_URL)
+            fileserver_url: HTTP file server URL (defaults to DEFAULT_FILESERVER_URL)
+        """
+        self.broker_url = broker_url or self.DEFAULT_BROKER_URL
+        self.fileserver_url = fileserver_url or self.DEFAULT_FILESERVER_URL
+    
+    async def smartsend(
+        self,
+        subject: str,
+        data: List[Tuple[str, Any, str]],
+        **kwargs
+    ) -> Tuple[Dict, str]:
+        """
+        Send data via NATS.
+        
+        Args:
+            subject: NATS subject to publish to
+            data: List of (dataname, data, type) tuples
+            **kwargs: Additional options passed to smartsend
+        
+        Returns:
+            Tuple of (env, env_json_str)
+        """
+        kwargs['broker_url'] = kwargs.get('broker_url', self.broker_url)
+        kwargs['fileserver_url'] = kwargs.get('fileserver_url', self.fileserver_url)
+        return await smartsend(subject, data, **kwargs)
+    
+    async def smartreceive(
+        self,
+        msg: Any,
+        **kwargs
+    ) -> Dict[str, Any]:
+        """
+        Receive and process NATS message.
+        
+        Args:
+            msg: NATS message to process
+            **kwargs: Additional options passed to smartreceive
+        
+        Returns:
+            Dict with envelope metadata and payloads
+        """
+        return await smartreceive(msg, **kwargs)
+
+
+# Convenience functions for module-level usage
+def send(
+    subject: str,
+    data: List[Tuple[str, Any, str]],
+    **kwargs
+) -> Tuple[Dict, str]:
+    """
+    Convenience function for sending data.
+    
+    Args:
+        subject: NATS subject to publish to
+        data: List of (dataname, data, type) tuples
+        **kwargs: Additional options
+    
+    Returns:
+        Tuple of (env, env_json_str)
+    """
+    return asyncio.run(smartsend(subject, data, **kwargs))
+
+
+def receive(
+    msg: Any,
+    **kwargs
+) -> Dict[str, Any]:
+    """
+    Convenience function for receiving messages.
+    
+    Args:
+        msg: NATS message to process
+        **kwargs: Additional options
+    
+    Returns:
+        Dict with envelope metadata and payloads
+    """
+    return asyncio.run(smartreceive(msg, **kwargs))
+
+
+__all__ = [
+    'smartsend',
+    'smartreceive',
+    'plik_oneshot_upload',
+    'fetch_with_backoff',
+    'NATSBridge',
+    'send',
+    'receive',
+    'DEFAULT_SIZE_THRESHOLD',
+    'DEFAULT_BROKER_URL',
+    'DEFAULT_FILESERVER_URL',
+    'NATSClient',
+    '_serialize_data',
+    '_deserialize_data',
+    'log_trace',
+    'publish_message'
+]

src/natsbridge_mpy.py

@@ -0,0 +1,673 @@
+"""
+NATSBridge - Cross-Platform Bi-Directional Data Bridge
+MicroPython Implementation
+
+This module provides functionality for sending and receiving data across network boundaries
+using NATS as the message bus, with support for both direct payload transport and
+URL-based transport for larger payloads.
+
+Note: MicroPython has significant constraints compared to desktop implementations:
+- Limited memory (~256KB - 1MB)
+- No Arrow IPC support (memory constraints)
+- Synchronous API (no async/await)
+- Lower size threshold for direct transport
+"""
+
+import network
+import time
+import json
+import base64
+import uos
+import struct
+import random
+
+# ---------------------------------------------- Constants ---------------------------------------------- #
+
+"""
+Default size threshold for switching from direct to link transport (100KB for MicroPython)
+"""
+DEFAULT_SIZE_THRESHOLD = 100000
+
+"""
+Default NATS server URL
+"""
+DEFAULT_BROKER_URL = "nats://localhost:4222"
+
+"""
+Default HTTP file server URL for link transport
+"""
+DEFAULT_FILESERVER_URL = "http://localhost:8080"
+
+"""
+Hard limit for payload size in MicroPython (50KB)
+"""
+MAX_PAYLOAD_SIZE = 50000
+
+
+# ---------------------------------------------- Utility Functions ---------------------------------------------- #
+
+def log_trace(correlation_id, message):
+    """
+    Log a trace message with correlation ID and timestamp.
+    
+    Args:
+        correlation_id: Correlation ID for tracing
+        message: Message content to log
+    """
+    timestamp = time.strftime('%Y-%m-%dT%H:%M:%SZ', time.localtime())
+    print(f"[{timestamp}] [Correlation: {correlation_id}] {message}")
+
+
+def _generate_uuid():
+    """
+    Generate a simple UUID compatible with MicroPython.
+    
+    Returns:
+        UUID string
+    """
+    # Generate a simple UUID-like string
+    # Format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+    hex_chars = '0123456789abcdef'
+    uuid_str = ''.join([random.choice(hex_chars) for _ in range(32)])
+    # Insert hyphens at proper positions
+    return f"{uuid_str[:8]}-{uuid_str[8:12]}-{uuid_str[12:16]}-{uuid_str[16:20]}-{uuid_str[20:]}"
+
+
+# ---------------------------------------------- Serialization Functions ---------------------------------------------- #
+
+def _serialize_data(data, payload_type):
+    """
+    Serialize data according to specified format.
+    
+    Args:
+        data: Data to serialize (string for "text", dict for "dictionary",
+              bytes for "image", "audio", "video", "binary")
+        payload_type: Target format: "text", "dictionary", "image", "audio", "video", "binary"
+    
+    Returns:
+        Binary representation of the serialized data
+    
+    Note:
+        MicroPython does not support "table" type due to memory constraints.
+    
+    Raises:
+        ValueError: If payload_type is not one of the supported types
+    """
+    if payload_type == 'text':
+        if isinstance(data, str):
+            return data.encode('utf-8')
+        else:
+            raise ValueError('Text data must be a string')
+    elif payload_type == 'dictionary':
+        json_str = json.dumps(data)
+        return json_str.encode('utf-8')
+    elif payload_type in ('image', 'audio', 'video', 'binary'):
+        if isinstance(data, (bytes, bytearray, memoryview)):
+            return bytes(data)
+        else:
+            raise ValueError(f'{payload_type} data must be bytes')
+    else:
+        raise ValueError(f'Unknown payload_type: {payload_type}')
+
+
+def _deserialize_data(data, payload_type):
+    """
+    Deserialize bytes to data based on type.
+    
+    Args:
+        data: Serialized data as bytes
+        payload_type: Data type ("text", "dictionary", "image", "audio", "video", "binary")
+    
+    Returns:
+        Deserialized data (String for "text", dict for "dictionary", bytes for others)
+    
+    Note:
+        MicroPython does not support "table" type due to memory constraints.
+    
+    Raises:
+        ValueError: If payload_type is not one of the supported types
+    """
+    if payload_type == 'text':
+        return data.decode('utf-8')
+    elif payload_type == 'dictionary':
+        json_str = data.decode('utf-8')
+        return json.loads(json_str)
+    elif payload_type in ('image', 'audio', 'video', 'binary'):
+        return data
+    else:
+        raise ValueError(f'Unknown payload_type: {payload_type}')
+
+
+# ---------------------------------------------- File Server Handlers ---------------------------------------------- #
+
+def _sync_fileserver_upload(file_server_url, dataname, data):
+    """
+    Synchronous file upload to HTTP server.
+    
+    Note:
+        This is a simplified implementation for MicroPython.
+        In practice, would use network.HTTP or similar.
+        Currently raises NotImplementedError as file upload is not fully supported.
+    
+    Args:
+        file_server_url: Base URL of the file server
+        dataname: Name of the file being uploaded
+        data: Raw byte data of the file content
+    
+    Returns:
+        Dict with keys: 'status', 'url'
+    
+    Raises:
+        NotImplementedError: File upload is not implemented in MicroPython
+    """
+    raise NotImplementedError("File upload not fully implemented in MicroPython. "
+                              "Use direct transport only for memory-constrained devices.")
+
+
+def _sync_fileserver_download(url, max_retries, base_delay, max_delay, correlation_id):
+    """
+    Synchronous file download with exponential backoff.
+    
+    Note:
+        This is a simplified implementation for MicroPython.
+        In practice, would use network.HTTP or similar.
+        Currently raises NotImplementedError as file download is not fully supported.
+    
+    Args:
+        url: URL to download from
+        max_retries: Maximum retry attempts
+        base_delay: Initial delay in ms
+        max_delay: Maximum delay in ms
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        Downloaded bytes
+    
+    Raises:
+        NotImplementedError: File download is not implemented in MicroPython
+    """
+    raise NotImplementedError("File download not fully implemented in MicroPython. "
+                              "Use direct transport only for memory-constrained devices.")
+
+
+# ---------------------------------------------- NATS Client ---------------------------------------------- #
+
+class NATSClient:
+    """
+    NATS client wrapper for MicroPython.
+    
+    Note:
+        This is a simplified implementation for MicroPython.
+        Full NATS client implementation would require additional network stack support.
+    """
+    
+    def __init__(self, url=DEFAULT_BROKER_URL):
+        """
+        Initialize NATS client.
+        
+        Args:
+            url: NATS server URL
+        """
+        self.url = url
+        self._connected = False
+    
+    def connect(self):
+        """
+        Connect to NATS server.
+        
+        Note:
+            This is a placeholder implementation.
+            Actual NATS client would require network stack support.
+        
+        Returns:
+            True if connected, False otherwise
+        """
+        # Placeholder - actual implementation would connect to NATS server
+        self._connected = True
+        return self._connected
+    
+    def publish(self, subject, message):
+        """
+        Publish message to NATS subject.
+        
+        Note:
+            This is a placeholder implementation.
+            Actual NATS client would require network stack support.
+        
+        Args:
+            subject: NATS subject to publish to
+            message: Message to publish
+        """
+        if not self._connected:
+            raise RuntimeError("Not connected to NATS server")
+        # Placeholder - actual implementation would publish to NATS
+        print(f"[NATS] Publish to {subject}: {message[:50]}...")
+    
+    def close(self):
+        """Close the NATS connection."""
+        self._connected = False
+
+
+# ---------------------------------------------- Core Functions ---------------------------------------------- #
+
+def _build_envelope(subject, payloads, options):
+    """
+    Build message envelope from payloads and metadata.
+    
+    Args:
+        subject: NATS subject
+        payloads: Array of payload objects
+        options: Envelope metadata options
+    
+    Returns:
+        Envelope dict
+    """
+    return {
+        'correlation_id': options['correlation_id'],
+        'msg_id': options['msg_id'],
+        'timestamp': time.strftime('%Y-%m-%dT%H:%M:%SZ', time.localtime()),
+        'send_to': subject,
+        'msg_purpose': options['msg_purpose'],
+        'sender_name': options['sender_name'],
+        'sender_id': options['sender_id'],
+        'receiver_name': options['receiver_name'],
+        'receiver_id': options['receiver_id'],
+        'reply_to': options['reply_to'],
+        'reply_to_msg_id': options['reply_to_msg_id'],
+        'broker_url': options['broker_url'],
+        'metadata': {},
+        'payloads': payloads
+    }
+
+
+def _build_payload(dataname, payload_type, payload_bytes, transport, data):
+    """
+    Build payload object from serialized data.
+    
+    Args:
+        dataname: Name of the payload
+        payload_type: Type of the payload
+        payload_bytes: Serialized payload bytes
+        transport: Transport type ("direct" or "link")
+        data: Data (base64 for direct, URL for link)
+    
+    Returns:
+        Payload dict
+    """
+    return {
+        'id': _generate_uuid(),
+        'dataname': dataname,
+        'payload_type': payload_type,
+        'transport': transport,
+        'encoding': 'base64' if transport == 'direct' else 'none',
+        'size': len(payload_bytes),
+        'data': data,
+        'metadata': {'payload_bytes': len(payload_bytes)} if transport == 'direct' else {}
+    }
+
+
+def _publish(subject, message, correlation_id):
+    """
+    Publish message to NATS.
+    
+    Note:
+        This is a simplified implementation for MicroPython.
+    
+    Args:
+        subject: NATS subject to publish to
+        message: JSON message to publish
+        correlation_id: Correlation ID for logging
+    """
+    log_trace(correlation_id, f"Publishing to {subject}")
+    # Placeholder - actual implementation would use NATSClient
+    # client = NATSClient()
+    # client.connect()
+    # client.publish(subject, message)
+    # client.close()
+
+
+def smartsend(subject, data, **kwargs):
+    """
+    Send data via NATS with automatic transport selection.
+    
+    This function intelligently routes data delivery based on payload size.
+    If the serialized payload is smaller than size_threshold, it encodes the data as Base64
+    and publishes directly over NATS. Otherwise, it uploads the data to a fileserver
+    and publishes only the download URL over NATS.
+    
+    Note:
+        MicroPython has memory constraints, so the default size_threshold is lower (100KB).
+        Table type is not supported due to memory constraints.
+    
+    Args:
+        subject: NATS subject to publish the message to
+        data: List of (dataname, data, type) tuples to send
+            - dataname: Name of the payload
+            - data: The actual data to send
+            - type: Payload type: "text", "dictionary", "image", "audio", "video", "binary"
+        broker_url: NATS server URL (default: DEFAULT_BROKER_URL)
+        fileserver_url: HTTP file server URL (default: DEFAULT_FILESERVER_URL)
+        fileserver_upload_handler: Function to handle fileserver uploads (default: _sync_fileserver_upload)
+        size_threshold: Threshold in bytes separating direct vs link transport (default: 100000)
+        correlation_id: Correlation ID for tracing (auto-generated if not provided)
+        msg_purpose: Purpose of the message (default: "chat")
+        sender_name: Name of the sender (default: "NATSBridge")
+        receiver_name: Name of the receiver (empty means broadcast)
+        receiver_id: UUID of the receiver (empty means broadcast)
+        reply_to: Topic to reply to (empty if no reply expected)
+        reply_to_msg_id: Message ID this message is replying to
+        is_publish: Whether to automatically publish the message (default: True)
+        msg_id: Message ID (auto-generated if not provided)
+        sender_id: Sender ID (auto-generated if not provided)
+    
+    Returns:
+        Tuple of (env, env_json_str) where:
+            - env: Dict containing all metadata and payloads
+            - env_json_str: JSON string for publishing to NATS
+    
+    Example:
+        >>> # Send text payload
+        >>> env, env_json_str = NATSBridge.smartsend(
+        ...     "/chat",
+        ...     [("message", "Hello!", "text")],
+        ...     broker_url="nats://localhost:4222"
+        ... )
+        >>>
+        >>> # Send dictionary payload
+        >>> env, env_json_str = NATSBridge.smartsend(
+        ...     "/config",
+        ...     [("config", {"key": "value"}, "dictionary")],
+        ...     broker_url="nats://localhost:4222"
+        ... )
+        >>>
+        >>> # Send binary payload (image, audio, video)
+        >>> env, env_json_str = NATSBridge.smartsend(
+        ...     "/media",
+        ...     [("image", image_bytes, "image")],
+        ...     broker_url="nats://localhost:4222"
+        ... )
+    """
+    # Extract options with defaults
+    correlation_id = kwargs.get('correlation_id', _generate_uuid())
+    msg_id = kwargs.get('msg_id', _generate_uuid())
+    sender_id = kwargs.get('sender_id', _generate_uuid())
+    broker_url = kwargs.get('broker_url', DEFAULT_BROKER_URL)
+    fileserver_url = kwargs.get('fileserver_url', DEFAULT_FILESERVER_URL)
+    size_threshold = kwargs.get('size_threshold', DEFAULT_SIZE_THRESHOLD)
+    msg_purpose = kwargs.get('msg_purpose', 'chat')
+    sender_name = kwargs.get('sender_name', 'NATSBridge')
+    receiver_name = kwargs.get('receiver_name', '')
+    receiver_id = kwargs.get('receiver_id', '')
+    reply_to = kwargs.get('reply_to', '')
+    reply_to_msg_id = kwargs.get('reply_to_msg_id', '')
+    is_publish = kwargs.get('is_publish', True)
+    fileserver_upload_handler = kwargs.get('fileserver_upload_handler', _sync_fileserver_upload)
+    
+    log_trace(correlation_id, f"Starting smartsend for subject: {subject}")
+    
+    # Process payloads
+    payloads = []
+    for dataname, payload_data, payload_type in data:
+        payload_bytes = _serialize_data(payload_data, payload_type)
+        payload_size = len(payload_bytes)
+        
+        # Check against hard limit for MicroPython
+        if payload_size > MAX_PAYLOAD_SIZE:
+            raise MemoryError(f"Payload '{dataname}' exceeds max size {MAX_PAYLOAD_SIZE} bytes")
+        
+        log_trace(correlation_id, f"Serialized payload '{dataname}' (type: {payload_type}) size: {payload_size} bytes")
+        
+        if payload_size < size_threshold:
+            # Direct path
+            payload_b64 = base64.b64encode(payload_bytes).decode('ascii')
+            log_trace(correlation_id, f"Using direct transport for {payload_size} bytes")
+            
+            payload = _build_payload(dataname, payload_type, payload_bytes, 'direct', payload_b64)
+            payloads.append(payload)
+        else:
+            # Link path (limited support)
+            log_trace(correlation_id, "Using link transport, uploading to fileserver")
+            
+            try:
+                response = fileserver_upload_handler(fileserver_url, dataname, payload_bytes)
+                log_trace(correlation_id, f"Uploaded to URL: {response['url']}")
+                
+                payload = _build_payload(dataname, payload_type, payload_bytes, 'link', response['url'])
+                payloads.append(payload)
+            except NotImplementedError:
+                # Fall back to direct transport if file upload not available
+                log_trace(correlation_id, "File upload not available, using direct transport")
+                payload_b64 = base64.b64encode(payload_bytes).decode('ascii')
+                payload = _build_payload(dataname, payload_type, payload_bytes, 'direct', payload_b64)
+                payloads.append(payload)
+    
+    # Build envelope
+    env = _build_envelope(subject, payloads, {
+        'correlation_id': correlation_id,
+        'msg_id': msg_id,
+        'msg_purpose': msg_purpose,
+        'sender_name': sender_name,
+        'sender_id': sender_id,
+        'receiver_name': receiver_name,
+        'receiver_id': receiver_id,
+        'reply_to': reply_to,
+        'reply_to_msg_id': reply_to_msg_id,
+        'broker_url': broker_url
+    })
+    
+    env_json_str = json.dumps(env)
+    
+    if is_publish:
+        _publish(subject, env_json_str, correlation_id)
+    
+    return env, env_json_str
+
+
+def smartreceive(msg, **kwargs):
+    """
+    Receive and process NATS message.
+    
+    This function processes incoming NATS messages, handling both direct transport
+    (base64 decoded payloads) and link transport (URL-based payloads).
+    It deserializes the data based on the transport type and returns the result.
+    
+    Note:
+        MicroPython has memory constraints, so large payloads should be avoided.
+        Table type is not supported due to memory constraints.
+    
+    Args:
+        msg: NATS message to process (can be string, dict, or object with 'payload' attribute)
+        fileserver_download_handler: Function to handle downloading data from file server URLs
+        max_retries: Maximum retry attempts (default: 3)
+        base_delay: Initial delay in ms (default: 100)
+        max_delay: Maximum delay in ms (default: 1000)
+    
+    Returns:
+        Dict with envelope metadata and payloads field containing List[Tuple[str, Any, str]]
+    
+    Example:
+        >>> # Receive and process message
+        >>> env = NATSBridge.smartreceive(msg, fileserver_download_handler=_sync_fileserver_download)
+        >>> # env is a Dict with "payloads" key containing List[Tuple[str, Any, str]]
+        >>> for dataname, data, type_ in env["payloads"]:
+        ...     print(f"{dataname}: {data} (type: {type_})")
+    """
+    # Parse the JSON envelope
+    if isinstance(msg, dict):
+        # Already parsed
+        env_json_obj = msg
+    elif hasattr(msg, 'payload'):
+        # Object with payload attribute
+        payload = msg.payload if isinstance(msg.payload, str) else msg.payload.decode('utf-8')
+        env_json_obj = json.loads(payload)
+    else:
+        # Assume it's already a JSON string or dict
+        env_json_obj = json.loads(msg) if isinstance(msg, str) else msg
+    
+    correlation_id = env_json_obj['correlation_id']
+    log_trace(correlation_id, "Processing received message")
+    
+    # Process all payloads in the envelope
+    payloads_list = []
+    num_payloads = len(env_json_obj['payloads'])
+    
+    for i in range(num_payloads):
+        payload_obj = env_json_obj['payloads'][i]
+        transport = payload_obj['transport']
+        dataname = payload_obj['dataname']
+        
+        if transport == 'direct':
+            log_trace(correlation_id, f"Direct transport - decoding payload '{dataname}'")
+            
+            # Extract base64 payload from the payload
+            payload_b64 = payload_obj['data']
+            
+            # Decode Base64 payload
+            payload_bytes = base64.b64decode(payload_b64)
+            
+            # Deserialize based on type
+            data_type = payload_obj['payload_type']
+            data = _deserialize_data(payload_bytes, data_type)
+            
+            payloads_list.append((dataname, data, data_type))
+        elif transport == 'link':
+            # Extract download URL from the payload
+            url = payload_obj['data']
+            log_trace(correlation_id, f"Link transport - fetching '{dataname}' from URL: {url}")
+            
+            # Fetch with exponential backoff using the download handler
+            fileserver_download_handler = kwargs.get('fileserver_download_handler', _sync_fileserver_download)
+            max_retries = kwargs.get('max_retries', 3)
+            base_delay = kwargs.get('base_delay', 100)
+            max_delay = kwargs.get('max_delay', 1000)
+            
+            downloaded_data = fileserver_download_handler(
+                url,
+                max_retries,
+                base_delay,
+                max_delay,
+                correlation_id
+            )
+            
+            # Deserialize based on type
+            data_type = payload_obj['payload_type']
+            data = _deserialize_data(downloaded_data, data_type)
+            
+            payloads_list.append((dataname, data, data_type))
+        else:
+            raise ValueError(f"Unknown transport type for payload '{dataname}': {transport}")
+    
+    env_json_obj['payloads'] = payloads_list
+    return env_json_obj
+
+
+# ---------------------------------------------- Module Exports ---------------------------------------------- #
+
+class NATSBridge:
+    """
+    MicroPython NATS bridge implementation.
+    
+    This class provides a convenient interface for NATSBridge functionality,
+    encapsulating the main functions and providing a class-based API.
+    
+    Note:
+        MicroPython has significant constraints:
+        - No Arrow IPC support (memory constraints)
+        - Only direct transport (< 100KB threshold enforced)
+        - Simplified UUID generation
+        - No async/await (synchronous API)
+    """
+    
+    DEFAULT_SIZE_THRESHOLD = DEFAULT_SIZE_THRESHOLD
+    DEFAULT_BROKER_URL = DEFAULT_BROKER_URL
+    DEFAULT_FILESERVER_URL = DEFAULT_FILESERVER_URL
+    MAX_PAYLOAD_SIZE = MAX_PAYLOAD_SIZE
+    
+    def __init__(self, broker_url=None, fileserver_url=None):
+        """
+        Initialize NATSBridge.
+        
+        Args:
+            broker_url: NATS server URL (defaults to DEFAULT_BROKER_URL)
+            fileserver_url: HTTP file server URL (defaults to DEFAULT_FILESERVER_URL)
+        """
+        self.broker_url = broker_url or self.DEFAULT_BROKER_URL
+        self.fileserver_url = fileserver_url or self.DEFAULT_FILESERVER_URL
+    
+    def smartsend(self, subject, data, **kwargs):
+        """
+        Send data via NATS.
+        
+        Args:
+            subject: NATS subject to publish to
+            data: List of (dataname, data, type) tuples
+            **kwargs: Additional options passed to smartsend
+        
+        Returns:
+            Tuple of (env, env_json_str)
+        """
+        kwargs['broker_url'] = kwargs.get('broker_url', self.broker_url)
+        kwargs['fileserver_url'] = kwargs.get('fileserver_url', self.fileserver_url)
+        return smartsend(subject, data, **kwargs)
+    
+    def smartreceive(self, msg, **kwargs):
+        """
+        Receive and process NATS message.
+        
+        Args:
+            msg: NATS message to process
+            **kwargs: Additional options passed to smartreceive
+        
+        Returns:
+            Dict with envelope metadata and payloads
+        """
+        return smartreceive(msg, **kwargs)
+
+
+# Convenience functions for module-level usage
+def send(subject, data, **kwargs):
+    """
+    Convenience function for sending data.
+    
+    Args:
+        subject: NATS subject to publish to
+        data: List of (dataname, data, type) tuples
+        **kwargs: Additional options
+    
+    Returns:
+        Tuple of (env, env_json_str)
+    """
+    return smartsend(subject, data, **kwargs)
+
+
+def receive(msg, **kwargs):
+    """
+    Convenience function for receiving messages.
+    
+    Args:
+        msg: NATS message to process
+        **kwargs: Additional options
+    
+    Returns:
+        Dict with envelope metadata and payloads
+    """
+    return smartreceive(msg, **kwargs)
+
+
+__all__ = [
+    'smartsend',
+    'smartreceive',
+    'NATSBridge',
+    'send',
+    'receive',
+    'DEFAULT_SIZE_THRESHOLD',
+    'DEFAULT_BROKER_URL',
+    'DEFAULT_FILESERVER_URL',
+    'MAX_PAYLOAD_SIZE',
+    'NATSClient',
+    '_serialize_data',
+    '_deserialize_data',
+    'log_trace',
+    '_sync_fileserver_upload',
+    '_sync_fileserver_download'
+]

test/test_js_binary_receiver.js

@@ -0,0 +1,216 @@
+/**
+ * JavaScript Binary Receiver Test
+ * Tests the smartreceive function with binary/image/audio/video payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Binary Receiver Test ===\n');
+    
+    // Create mock NATS message with binary payloads
+    const binaryData = Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]); // PNG header
+    const audioData = Buffer.from([0x46, 0x4C, 0x41, 0x43, 0x00, 0x00, 0x00, 0x00]); // FLAC header
+    const videoData = Buffer.from([0x00, 0x00, 0x00, 0x18, 0x66, 0x74, 0x79, 0x70]); // MP4 header
+    const genericBinary = Buffer.from([0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE]);
+    
+    const testData = {
+        correlation_id: 'js-binary-receiver-' + crypto.randomUUID(),
+        msg_id: 'msg-' + crypto.randomUUID(),
+        timestamp: new Date().toISOString(),
+        send_to: '/test/binary',
+        msg_purpose: 'test',
+        sender_name: 'js-binary-test',
+        sender_id: 'sender-' + crypto.randomUUID(),
+        receiver_name: 'js-receiver',
+        receiver_id: 'receiver-' + crypto.randomUUID(),
+        reply_to: '',
+        reply_to_msg_id: '',
+        broker_url: TEST_BROKER_URL,
+        metadata: {},
+        payloads: [
+            {
+                id: 'payload-1',
+                dataname: 'image',
+                payload_type: 'image',
+                transport: 'direct',
+                encoding: 'base64',
+                size: binaryData.length,
+                data: binaryData.toString('base64'),
+                metadata: { payload_bytes: binaryData.length }
+            },
+            {
+                id: 'payload-2',
+                dataname: 'audio',
+                payload_type: 'audio',
+                transport: 'direct',
+                encoding: 'base64',
+                size: audioData.length,
+                data: audioData.toString('base64'),
+                metadata: { payload_bytes: audioData.length }
+            },
+            {
+                id: 'payload-3',
+                dataname: 'video',
+                payload_type: 'video',
+                transport: 'direct',
+                encoding: 'base64',
+                size: videoData.length,
+                data: videoData.toString('base64'),
+                metadata: { payload_bytes: videoData.length }
+            },
+            {
+                id: 'payload-4',
+                dataname: 'binary',
+                payload_type: 'binary',
+                transport: 'direct',
+                encoding: 'base64',
+                size: genericBinary.length,
+                data: genericBinary.toString('base64'),
+                metadata: { payload_bytes: genericBinary.length }
+            }
+        ]
+    };
+    
+    const mockMsg = {
+        payload: JSON.stringify(testData)
+    };
+    
+    console.log('Mock Message Created:');
+    console.log(`  Correlation ID: ${testData.correlation_id}`);
+    console.log(`  Payloads: ${testData.payloads.length}`);
+    console.log(`  Payload types: ${testData.payloads.map(p => p.payload_type).join(', ')}\n`);
+    
+    try {
+        // Receive and process the message
+        console.log('Receiving and processing message...');
+        const env = await NATSBridge.smartreceive(
+            mockMsg,
+            {
+                max_retries: 3,
+                base_delay: 100,
+                max_delay: 1000
+            }
+        );
+        
+        console.log('\n=== Received Envelope ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate received data
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (!env.correlation_id) {
+            console.log('❌ correlation_id is missing');
+            passed = false;
+        } else {
+            console.log('✅ correlation_id present');
+        }
+        
+        if (env.payloads.length !== 4) {
+            console.log(`❌ Expected 4 payloads, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        // Expected data
+        const expectedData = [
+            ['image', binaryData, 'image'],
+            ['audio', audioData, 'audio'],
+            ['video', videoData, 'video'],
+            ['binary', genericBinary, 'binary']
+        ];
+        
+        for (let i = 0; i < env.payloads.length; i++) {
+            const payload = env.payloads[i];
+            const expected = expectedData[i];
+            
+            if (payload[0] !== expected[0]) {
+                console.log(`❌ Payload ${i + 1}: Expected dataname '${expected[0]}', got '${payload[0]}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct dataname`);
+            }
+            
+            if (payload[2] !== expected[2]) {
+                console.log(`❌ Payload ${i + 1}: Expected type '${expected[2]}', got '${payload[2]}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct type`);
+            }
+            
+            // Verify binary data integrity
+            const receivedData = payload[1];
+            if (!(receivedData instanceof Buffer || receivedData instanceof Uint8Array)) {
+                console.log(`❌ Payload ${i + 1}: Expected Buffer/Uint8Array, got ${typeof receivedData}`);
+                passed = false;
+            } else if (Buffer.isBuffer(receivedData)) {
+                if (receivedData.length !== expected[1].length) {
+                    console.log(`❌ Payload ${i + 1}: Length mismatch`);
+                    passed = false;
+                } else {
+                    let dataMatch = true;
+                    for (let j = 0; j < expected[1].length; j++) {
+                        if (receivedData[j] !== expected[1][j]) {
+                            dataMatch = false;
+                            break;
+                        }
+                    }
+                    if (dataMatch) {
+                        console.log(`✅ Payload ${i + 1}: Data correctly deserialized`);
+                    } else {
+                        console.log(`❌ Payload ${i + 1}: Data mismatch`);
+                        passed = false;
+                    }
+                }
+            } else {
+                // Uint8Array comparison
+                const receivedBuffer = Buffer.from(receivedData);
+                if (receivedBuffer.length !== expected[1].length) {
+                    console.log(`❌ Payload ${i + 1}: Length mismatch`);
+                    passed = false;
+                } else {
+                    let dataMatch = true;
+                    for (let j = 0; j < expected[1].length; j++) {
+                        if (receivedBuffer[j] !== expected[1][j]) {
+                            dataMatch = false;
+                            break;
+                        }
+                    }
+                    if (dataMatch) {
+                        console.log(`✅ Payload ${i + 1}: Data correctly deserialized`);
+                    } else {
+                        console.log(`❌ Payload ${i + 1}: Data mismatch`);
+                        passed = false;
+                    }
+                }
+            }
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_binary_sender.js

@@ -0,0 +1,174 @@
+/**
+ * JavaScript Binary Sender Test
+ * Tests the smartsend function with binary/image/audio/video payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_SUBJECT = '/test/binary';
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Binary Sender Test ===\n');
+    
+    const correlationId = crypto.randomUUID();
+    console.log(`Correlation ID: ${correlationId}`);
+    console.log(`Subject: ${TEST_SUBJECT}`);
+    console.log(`Broker URL: ${TEST_BROKER_URL}\n`);
+    
+    // Test data - binary data for different types
+    const binaryData = Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]); // PNG header
+    const audioData = Buffer.from([0x46, 0x4C, 0x41, 0x43, 0x00, 0x00, 0x00, 0x00]); // FLAC header
+    const videoData = Buffer.from([0x00, 0x00, 0x00, 0x18, 0x66, 0x74, 0x79, 0x70]); // MP4 header
+    const genericBinary = Buffer.from([0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE]);
+    
+    const testData = [
+        ['image', binaryData, 'image'],
+        ['audio', audioData, 'audio'],
+        ['video', videoData, 'video'],
+        ['binary', genericBinary, 'binary']
+    ];
+    
+    try {
+        // Send the message
+        console.log('Sending binary payloads...');
+        const [env, envJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            testData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: correlationId,
+                msg_purpose: 'test',
+                sender_name: 'js-binary-test',
+                is_publish: false
+            }
+        );
+        
+        console.log('\n=== Envelope Created ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Purpose: ${env.msg_purpose}`);
+        console.log(`Sender: ${env.sender_name}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate envelope structure
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (env.payloads.length !== 4) {
+            console.log(`❌ Expected 4 payloads, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        // Test each payload
+        const expectedDatanames = ['image', 'audio', 'video', 'binary'];
+        const expectedTypes = ['image', 'audio', 'video', 'binary'];
+        const expectedData = [binaryData, audioData, videoData, genericBinary];
+        
+        for (let i = 0; i < env.payloads.length; i++) {
+            const payload = env.payloads[i];
+            
+            if (payload.dataname !== expectedDatanames[i]) {
+                console.log(`❌ Payload ${i + 1}: Expected dataname '${expectedDatanames[i]}', got '${payload.dataname}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct dataname`);
+            }
+            
+            if (payload.payload_type !== expectedTypes[i]) {
+                console.log(`❌ Payload ${i + 1}: Expected type '${expectedTypes[i]}', got '${payload.payload_type}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct type`);
+            }
+            
+            if (payload.transport !== 'direct') {
+                console.log(`❌ Payload ${i + 1}: Expected transport 'direct', got '${payload.transport}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct transport`);
+            }
+            
+            if (payload.encoding !== 'base64') {
+                console.log(`❌ Payload ${i + 1}: Expected encoding 'base64', got '${payload.encoding}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct encoding`);
+            }
+            
+            // Decode and verify the data
+            const decodedData = Buffer.from(payload.data, 'base64');
+            const originalData = expectedData[i];
+            
+            if (decodedData.length !== originalData.length) {
+                console.log(`❌ Payload ${i + 1}: Length mismatch (${decodedData.length} vs ${originalData.length})`);
+                passed = false;
+            } else {
+                let dataMatch = true;
+                for (let j = 0; j < originalData.length; j++) {
+                    if (decodedData[j] !== originalData[j]) {
+                        dataMatch = false;
+                        break;
+                    }
+                }
+                if (dataMatch) {
+                    console.log(`✅ Payload ${i + 1}: Data integrity verified`);
+                } else {
+                    console.log(`❌ Payload ${i + 1}: Data integrity mismatch`);
+                    passed = false;
+                }
+            }
+            
+            console.log(`   Size: ${payload.size} bytes\n`);
+        }
+        
+        // Test with larger binary data (simulating file upload scenario)
+        console.log('=== Large Binary Data Test ===');
+        const largeData = Buffer.alloc(10000, 0xFF); // 10KB of binary data
+        const largeTestData = [
+            ['large_binary', largeData, 'binary']
+        ];
+        
+        const [largeEnv, _] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            largeTestData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: 'large-' + correlationId,
+                is_publish: false
+            }
+        );
+        
+        if (largeEnv.payloads.length === 1 && largeEnv.payloads[0].size === 10000) {
+            console.log('✅ Large binary data handled correctly');
+        } else {
+            console.log('❌ Large binary data handling failed');
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_dictionary_receiver.js

@@ -0,0 +1,221 @@
+/**
+ * JavaScript Dictionary Receiver Test
+ * Tests the smartreceive function with dictionary payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Dictionary Receiver Test ===\n');
+    
+    // Create a mock NATS message with dictionary payloads
+    const simpleDict = { key1: 'value1', key2: 'value2' };
+    const nestedDict = { outer: { inner: 'value', number: 42 } };
+    const arrayDict = { items: [1, 2, 3, 'four', 'five'] };
+    const mixedDict = { string: 'text', number: 123, boolean: true, null_val: null };
+    
+    const testData = {
+        correlation_id: 'test-receiver-dict-' + crypto.randomUUID(),
+        msg_id: 'msg-' + crypto.randomUUID(),
+        timestamp: new Date().toISOString(),
+        send_to: '/test/dictionary',
+        msg_purpose: 'test',
+        sender_name: 'js-dict-test',
+        sender_id: 'sender-' + crypto.randomUUID(),
+        receiver_name: 'js-receiver',
+        receiver_id: 'receiver-' + crypto.randomUUID(),
+        reply_to: '',
+        reply_to_msg_id: '',
+        broker_url: TEST_BROKER_URL,
+        metadata: {},
+        payloads: [
+            {
+                id: 'payload-1',
+                dataname: 'simple_dict',
+                payload_type: 'dictionary',
+                transport: 'direct',
+                encoding: 'base64',
+                size: Buffer.from(JSON.stringify(simpleDict)).length,
+                data: Buffer.from(JSON.stringify(simpleDict)).toString('base64'),
+                metadata: { payload_bytes: Buffer.from(JSON.stringify(simpleDict)).length }
+            },
+            {
+                id: 'payload-2',
+                dataname: 'nested_dict',
+                payload_type: 'dictionary',
+                transport: 'direct',
+                encoding: 'base64',
+                size: Buffer.from(JSON.stringify(nestedDict)).length,
+                data: Buffer.from(JSON.stringify(nestedDict)).toString('base64'),
+                metadata: { payload_bytes: Buffer.from(JSON.stringify(nestedDict)).length }
+            },
+            {
+                id: 'payload-3',
+                dataname: 'array_dict',
+                payload_type: 'dictionary',
+                transport: 'direct',
+                encoding: 'base64',
+                size: Buffer.from(JSON.stringify(arrayDict)).length,
+                data: Buffer.from(JSON.stringify(arrayDict)).toString('base64'),
+                metadata: { payload_bytes: Buffer.from(JSON.stringify(arrayDict)).length }
+            },
+            {
+                id: 'payload-4',
+                dataname: 'mixed_dict',
+                payload_type: 'dictionary',
+                transport: 'direct',
+                encoding: 'base64',
+                size: Buffer.from(JSON.stringify(mixedDict)).length,
+                data: Buffer.from(JSON.stringify(mixedDict)).toString('base64'),
+                metadata: { payload_bytes: Buffer.from(JSON.stringify(mixedDict)).length }
+            }
+        ]
+    };
+    
+    const mockMsg = {
+        payload: JSON.stringify(testData)
+    };
+    
+    console.log('Mock Message Created:');
+    console.log(`  Correlation ID: ${testData.correlation_id}`);
+    console.log(`  Payloads: ${testData.payloads.length}`);
+    console.log(`  Payload types: ${testData.payloads.map(p => p.payload_type).join(', ')}\n`);
+    
+    try {
+        // Receive and process the message
+        console.log('Receiving and processing message...');
+        const env = await NATSBridge.smartreceive(
+            mockMsg,
+            {
+                max_retries: 3,
+                base_delay: 100,
+                max_delay: 1000
+            }
+        );
+        
+        console.log('\n=== Received Envelope ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate received data
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (!env.correlation_id) {
+            console.log('❌ correlation_id is missing');
+            passed = false;
+        } else {
+            console.log('✅ correlation_id present');
+        }
+        
+        if (env.payloads.length !== 4) {
+            console.log(`❌ Expected 4 payloads, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        // Expected data
+        const expectedData = [
+            ['simple_dict', simpleDict, 'dictionary'],
+            ['nested_dict', nestedDict, 'dictionary'],
+            ['array_dict', arrayDict, 'dictionary'],
+            ['mixed_dict', mixedDict, 'dictionary']
+        ];
+        
+        for (let i = 0; i < env.payloads.length; i++) {
+            const payload = env.payloads[i];
+            const expected = expectedData[i];
+            
+            if (payload[0] !== expected[0]) {
+                console.log(`❌ Payload ${i + 1}: Expected dataname '${expected[0]}', got '${payload[0]}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct dataname`);
+            }
+            
+            if (payload[2] !== expected[2]) {
+                console.log(`❌ Payload ${i + 1}: Expected type '${expected[2]}', got '${payload[2]}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct type`);
+            }
+            
+            const dataMatch = JSON.stringify(payload[1]) === JSON.stringify(expected[1]);
+            if (!dataMatch) {
+                console.log(`❌ Payload ${i + 1}: Data mismatch`);
+                console.log(`   Expected: ${JSON.stringify(expected[1])}`);
+                console.log(`   Got: ${JSON.stringify(payload[1])}`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Data correctly deserialized`);
+            }
+        }
+        
+        // Test round-trip with receive
+        console.log('\n=== Round-trip Test ===');
+        const roundTripData = {
+            correlation_id: 'roundtrip-' + crypto.randomUUID(),
+            msg_id: 'msg-' + crypto.randomUUID(),
+            timestamp: new Date().toISOString(),
+            send_to: '/test/dictionary',
+            msg_purpose: 'test',
+            sender_name: 'js-test',
+            sender_id: 'sender-' + crypto.randomUUID(),
+            receiver_name: 'js-receiver',
+            receiver_id: 'receiver-' + crypto.randomUUID(),
+            reply_to: '',
+            reply_to_msg_id: '',
+            broker_url: TEST_BROKER_URL,
+            metadata: {},
+            payloads: [
+                {
+                    id: 'payload-rt',
+                    dataname: 'roundtrip',
+                    payload_type: 'dictionary',
+                    transport: 'direct',
+                    encoding: 'base64',
+                    size: Buffer.from(JSON.stringify({ test: 'data', nested: { a: 1, b: 2 } })).length,
+                    data: Buffer.from(JSON.stringify({ test: 'data', nested: { a: 1, b: 2 } })).toString('base64'),
+                    metadata: { payload_bytes: Buffer.from(JSON.stringify({ test: 'data', nested: { a: 1, b: 2 } })).length }
+                }
+            ]
+        };
+        
+        const mockRtMsg = { payload: JSON.stringify(roundTripData) };
+        const rtEnv = await NATSBridge.smartreceive(mockRtMsg);
+        
+        if (rtEnv.payloads.length === 1 && 
+            rtEnv.payloads[0][0] === 'roundtrip' &&
+            rtEnv.payloads[0][2] === 'dictionary') {
+            console.log('✅ Round-trip test successful');
+        } else {
+            console.log('❌ Round-trip test failed');
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_dictionary_sender.js

@@ -0,0 +1,179 @@
+/**
+ * JavaScript Dictionary Sender Test
+ * Tests the smartsend function with dictionary payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_SUBJECT = '/test/dictionary';
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Dictionary Sender Test ===\n');
+    
+    const correlationId = crypto.randomUUID();
+    console.log(`Correlation ID: ${correlationId}`);
+    console.log(`Subject: ${TEST_SUBJECT}`);
+    console.log(`Broker URL: ${TEST_BROKER_URL}\n`);
+    
+    // Test data - various dictionary structures
+    const testData = [
+        ['simple_dict', { key1: 'value1', key2: 'value2' }, 'dictionary'],
+        ['nested_dict', { outer: { inner: 'value', number: 42 } }, 'dictionary'],
+        ['array_dict', { items: [1, 2, 3, 'four', 'five'] }, 'dictionary'],
+        ['mixed_dict', { string: 'text', number: 123, boolean: true, null_val: null }, 'dictionary']
+    ];
+    
+    try {
+        // Send the message
+        console.log('Sending dictionary payloads...');
+        const [env, envJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            testData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: correlationId,
+                msg_purpose: 'test',
+                sender_name: 'js-dict-test',
+                is_publish: false
+            }
+        );
+        
+        console.log('\n=== Envelope Created ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Purpose: ${env.msg_purpose}`);
+        console.log(`Sender: ${env.sender_name}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate envelope structure
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (env.payloads.length !== 4) {
+            console.log(`❌ Expected 4 payloads, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        // Test each payload
+        const expectedDatanames = ['simple_dict', 'nested_dict', 'array_dict', 'mixed_dict'];
+        const expectedTypes = ['dictionary', 'dictionary', 'dictionary', 'dictionary'];
+        
+        for (let i = 0; i < env.payloads.length; i++) {
+            const payload = env.payloads[i];
+            
+            if (payload.dataname !== expectedDatanames[i]) {
+                console.log(`❌ Payload ${i + 1}: Expected dataname '${expectedDatanames[i]}', got '${payload.dataname}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct dataname`);
+            }
+            
+            if (payload.payload_type !== expectedTypes[i]) {
+                console.log(`❌ Payload ${i + 1}: Expected type '${expectedTypes[i]}', got '${payload.payload_type}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct type`);
+            }
+            
+            if (payload.transport !== 'direct') {
+                console.log(`❌ Payload ${i + 1}: Expected transport 'direct', got '${payload.transport}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct transport`);
+            }
+            
+            if (payload.encoding !== 'base64') {
+                console.log(`❌ Payload ${i + 1}: Expected encoding 'base64', got '${payload.encoding}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct encoding`);
+            }
+            
+            // Decode and verify the data
+            const decodedData = JSON.parse(Buffer.from(payload.data, 'base64').toString('utf8'));
+            const originalData = testData[i][1];
+            
+            const originalJson = JSON.stringify(originalData);
+            const decodedJson = JSON.stringify(decodedData);
+            
+            if (originalJson !== decodedJson) {
+                console.log(`❌ Payload ${i + 1}: Data integrity mismatch`);
+                console.log(`   Expected: ${originalJson}`);
+                console.log(`   Got: ${decodedJson}`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Data integrity verified`);
+            }
+            
+            console.log(`   Size: ${payload.size} bytes\n`);
+        }
+        
+        // Test round-trip serialization
+        console.log('=== Round-trip Serialization Test ===');
+        const roundTripTestData = [
+            ['roundtrip', { test: 'data', numbers: [1, 2, 3], nested: { a: 1, b: 2 } }, 'dictionary']
+        ];
+        
+        const [rtEnv, rtEnvJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            roundTripTestData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: 'roundtrip-' + correlationId,
+                is_publish: false
+            }
+        );
+        
+        const rtPayload = rtEnv.payloads[0];
+        const rtDecoded = JSON.parse(Buffer.from(rtPayload.data, 'base64').toString('utf8'));
+        
+        if (JSON.stringify(rtDecoded) === JSON.stringify(roundTripTestData[0][1])) {
+            console.log('✅ Round-trip serialization successful');
+        } else {
+            console.log('❌ Round-trip serialization failed');
+            passed = false;
+        }
+        
+        // Test JSON string output
+        console.log('\n=== JSON String Output Test ===');
+        try {
+            const parsed = JSON.parse(envJsonStr);
+            if (parsed.correlation_id === env.correlation_id && 
+                parsed.payloads.length === env.payloads.length) {
+                console.log('✅ JSON string is valid and matches envelope');
+            } else {
+                console.log('❌ JSON string does not match envelope');
+                passed = false;
+            }
+        } catch (e) {
+            console.log('❌ JSON string is invalid:', e.message);
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_mix_payloads_receiver.js

@@ -0,0 +1,216 @@
+/**
+ * JavaScript Mix Payloads Receiver Test
+ * Tests the smartreceive function with mixed payload types
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const nats = require('nats');
+const crypto = require('crypto');
+
+const TEST_SUBJECT = '/test/mix';
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Mix Payloads Receiver Test ===\n');
+
+    const correlationId = crypto.randomUUID();
+    console.log(`Correlation ID: ${correlationId}`);
+    console.log(`Subject: ${TEST_SUBJECT}`);
+    console.log(`Broker URL: ${TEST_BROKER_URL}\n`);
+
+    // Expected test data - same as sender
+    const expectedTextData = 'Hello, NATSBridge!';
+    const expectedDictData = { key1: 'value1', key2: 42, nested: { a: 1, b: 2 } };
+    const expectedBinaryData = Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]); // PNG header
+    const expectedTableData = [
+        { id: 1, name: 'Alice', age: 30 },
+        { id: 2, name: 'Bob', age: 25 },
+        { id: 3, name: 'Charlie', age: 35 }
+    ];
+
+    const expectedDatanames = ['message', 'config', 'image', 'users'];
+    const expectedTypes = ['text', 'dictionary', 'image', 'table'];
+
+    let testPassed = true;
+    let messagesReceived = 0;
+    const receivedPayloads = [];
+
+    try {
+        // Connect to NATS
+        console.log('Connecting to NATS server...');
+        const nc = await nats.connect({ servers: TEST_BROKER_URL });
+        console.log('✅ Connected to NATS server\n');
+
+        // Set up message subscription
+        const subscription = nc.subscribe(TEST_SUBJECT);
+
+        // Wait for messages with timeout
+        const messagePromise = new Promise(async (resolve, reject) => {
+            const timeout = setTimeout(() => {
+                resolve('timeout');
+            }, 10000); // 10 second timeout
+
+            (async () => {
+                for await (const msg of subscription) {
+                    clearTimeout(timeout);
+                    messagesReceived++;
+                    console.log(`\n=== Message ${messagesReceived} Received ===`);
+                    console.log(`Raw payload length: ${msg.payload.length} bytes`);
+
+                    try {
+                        // Process the message using smartreceive
+                        const envelope = await NATSBridge.smartreceive(msg, {
+                            fileserver_download_handler: NATSBridge.fetchWithBackoff,
+                            max_retries: 5,
+                            base_delay: 100,
+                            max_delay: 5000
+                        });
+
+                        console.log(`Correlation ID: ${envelope.correlation_id}`);
+                        console.log(`Message ID: ${envelope.msg_id}`);
+                        console.log(`Number of payloads: ${envelope.payloads.length}`);
+
+                        receivedPayloads.push(envelope);
+
+                        // Validate envelope structure
+                        console.log('\n=== Envelope Validation ===');
+
+                        if (envelope.payloads.length < 4) {
+                            console.log(`❌ Expected at least 4 payloads, got ${envelope.payloads.length}`);
+                            testPassed = false;
+                        } else {
+                            console.log(`✅ Correct number of payloads: ${envelope.payloads.length}`);
+                        }
+
+                        // Validate each payload
+                        for (let i = 0; i < envelope.payloads.length; i++) {
+                            const [dataname, data, dataType] = envelope.payloads[i];
+
+                            console.log(`\n--- Payload ${i + 1}: ${dataname} (type: ${dataType}) ---`);
+
+                            // Check dataname
+                            if (i < expectedDatanames.length && dataname !== expectedDatanames[i]) {
+                                console.log(`❌ Expected dataname '${expectedDatanames[i]}', got '${dataname}'`);
+                                testPassed = false;
+                            } else {
+                                console.log(`✅ Correct dataname: ${dataname}`);
+                            }
+
+                            // Check data type
+                            if (i < expectedTypes.length && dataType !== expectedTypes[i]) {
+                                console.log(`❌ Expected type '${expectedTypes[i]}', got '${dataType}'`);
+                                testPassed = false;
+                            } else {
+                                console.log(`✅ Correct type: ${dataType}`);
+                            }
+
+                            // Validate data based on type
+                            if (dataType === 'text') {
+                                if (typeof data === 'string' && data === expectedTextData) {
+                                    console.log(`✅ Text data verified: "${data}"`);
+                                } else {
+                                    console.log(`❌ Text data mismatch. Expected: "${expectedTextData}", Got: "${data}"`);
+                                    testPassed = false;
+                                }
+                            } else if (dataType === 'dictionary') {
+                                if (typeof data === 'object' && JSON.stringify(data) === JSON.stringify(expectedDictData)) {
+                                    console.log(`✅ Dictionary data verified`);
+                                    console.log(`   Keys: ${Object.keys(data).join(', ')}`);
+                                } else {
+                                    console.log(`❌ Dictionary data mismatch`);
+                                    console.log(`   Expected: ${JSON.stringify(expectedDictData)}`);
+                                    console.log(`   Got: ${JSON.stringify(data)}`);
+                                    testPassed = false;
+                                }
+                            } else if (dataType === 'image') {
+                                if (data instanceof Buffer || data instanceof Uint8Array) {
+                                    const dataBuffer = Buffer.isBuffer(data) ? data : Buffer.from(data);
+                                    if (dataBuffer.length === expectedBinaryData.length) {
+                                        let dataMatch = true;
+                                        for (let j = 0; j < expectedBinaryData.length; j++) {
+                                            if (dataBuffer[j] !== expectedBinaryData[j]) {
+                                                dataMatch = false;
+                                                break;
+                                            }
+                                        }
+                                        if (dataMatch) {
+                                            console.log(`✅ Image data verified (${dataBuffer.length} bytes)`);
+                                        } else {
+                                            console.log(`❌ Image data mismatch`);
+                                            testPassed = false;
+                                        }
+                                    } else {
+                                        console.log(`❌ Image data length mismatch. Expected: ${expectedBinaryData.length}, Got: ${dataBuffer.length}`);
+                                        testPassed = false;
+                                    }
+                                } else {
+                                    console.log(`❌ Image data is not a Buffer or Uint8Array`);
+                                    testPassed = false;
+                                }
+                            } else if (dataType === 'table') {
+                                // For table data, check if it's an Arrow table-like object
+                                if (data && typeof data === 'object') {
+                                    // Arrow tables have specific properties
+                                    if (data.numRows !== undefined && data.numCols !== undefined) {
+                                        console.log(`✅ Table data verified`);
+                                        console.log(`   Rows: ${data.numRows}, Columns: ${data.numCols}`);
+                                    } else {
+                                        console.log(`⚠️  Table data received but not standard Arrow format`);
+                                        console.log(`   Keys: ${Object.keys(data).join(', ')}`);
+                                    }
+                                } else {
+                                    console.log(`❌ Table data is not a valid object`);
+                                    testPassed = false;
+                                }
+                            }
+                        }
+
+                        // Stop after receiving at least one valid message
+                        if (messagesReceived >= 1) {
+                            resolve('done');
+                        }
+                    } catch (error) {
+                        console.error(`❌ Error processing message: ${error.message}`);
+                        console.error(error.stack);
+                        testPassed = false;
+                        resolve('error');
+                    }
+                }
+            })();
+        });
+
+        console.log('Waiting for messages...\n');
+
+        // Wait for message or timeout
+        const result = await messagePromise;
+
+        // Close NATS connection
+        await nc.close();
+        console.log('\n✅ NATS connection closed');
+
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (messagesReceived === 0) {
+            console.log('❌ NO MESSAGES RECEIVED');
+            console.log('Make sure to run the sender test first: node test/test_js_mix_payloads_sender.js');
+            process.exit(1);
+        } else if (result === 'error') {
+            console.log('❌ ERROR PROCESSING MESSAGES');
+            process.exit(1);
+        } else if (testPassed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_mix_payloads_sender.js

@@ -0,0 +1,205 @@
+/**
+ * JavaScript Mix Payloads Sender Test
+ * Tests the smartsend function with mixed payload types
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_SUBJECT = '/test/mix';
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Mix Payloads Sender Test ===\n');
+    
+    const correlationId = crypto.randomUUID();
+    console.log(`Correlation ID: ${correlationId}`);
+    console.log(`Subject: ${TEST_SUBJECT}`);
+    console.log(`Broker URL: ${TEST_BROKER_URL}\n`);
+    
+    // Test data - mixed payload types
+    const textData = 'Hello, NATSBridge!';
+    const dictData = { key1: 'value1', key2: 42, nested: { a: 1, b: 2 } };
+    const binaryData = Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]); // PNG header
+    
+    // Table data
+    const tableData = [
+        { id: 1, name: 'Alice', age: 30 },
+        { id: 2, name: 'Bob', age: 25 },
+        { id: 3, name: 'Charlie', age: 35 }
+    ];
+    
+    const testData = [
+        ['message', textData, 'text'],
+        ['config', dictData, 'dictionary'],
+        ['image', binaryData, 'image'],
+        ['users', tableData, 'table']
+    ];
+    
+    try {
+        // Send the message
+        console.log('Sending mixed payloads...');
+        const [env, envJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            testData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: correlationId,
+                msg_purpose: 'test',
+                sender_name: 'js-mix-test',
+                is_publish: false
+            }
+        );
+        
+        console.log('\n=== Envelope Created ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Purpose: ${env.msg_purpose}`);
+        console.log(`Sender: ${env.sender_name}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate envelope structure
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (env.payloads.length !== 4) {
+            console.log(`❌ Expected 4 payloads, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        // Test each payload
+        const expectedDatanames = ['message', 'config', 'image', 'users'];
+        const expectedTypes = ['text', 'dictionary', 'image', 'table'];
+        const expectedData = [textData, dictData, binaryData, tableData];
+        
+        for (let i = 0; i < env.payloads.length; i++) {
+            const payload = env.payloads[i];
+            
+            if (payload.dataname !== expectedDatanames[i]) {
+                console.log(`❌ Payload ${i + 1}: Expected dataname '${expectedDatanames[i]}', got '${payload.dataname}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct dataname`);
+            }
+            
+            if (payload.payload_type !== expectedTypes[i]) {
+                console.log(`❌ Payload ${i + 1}: Expected type '${expectedTypes[i]}', got '${payload.payload_type}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct type`);
+            }
+            
+            if (payload.transport !== 'direct') {
+                console.log(`❌ Payload ${i + 1}: Expected transport 'direct', got '${payload.transport}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct transport`);
+            }
+            
+            if (payload.encoding !== 'base64') {
+                console.log(`❌ Payload ${i + 1}: Expected encoding 'base64', got '${payload.encoding}'`);
+                passed = false;
+            } else {
+                console.log(`✅ Payload ${i + 1}: Correct encoding`);
+            }
+            
+            // Verify data integrity based on type
+            if (expectedTypes[i] === 'text') {
+                const decodedData = Buffer.from(payload.data, 'base64').toString('utf8');
+                if (decodedData !== expectedData[i]) {
+                    console.log(`❌ Payload ${i + 1}: Data integrity mismatch`);
+                    passed = false;
+                } else {
+                    console.log(`✅ Payload ${i + 1}: Data integrity verified`);
+                }
+            } else if (expectedTypes[i] === 'dictionary') {
+                const decodedData = JSON.parse(Buffer.from(payload.data, 'base64').toString('utf8'));
+                if (JSON.stringify(decodedData) !== JSON.stringify(expectedData[i])) {
+                    console.log(`❌ Payload ${i + 1}: Data integrity mismatch`);
+                    passed = false;
+                } else {
+                    console.log(`✅ Payload ${i + 1}: Data integrity verified`);
+                }
+            } else if (expectedTypes[i] === 'image') {
+                const decodedData = Buffer.from(payload.data, 'base64');
+                if (decodedData.length !== expectedData[i].length) {
+                    console.log(`❌ Payload ${i + 1}: Length mismatch`);
+                    passed = false;
+                } else {
+                    let dataMatch = true;
+                    for (let j = 0; j < expectedData[i].length; j++) {
+                        if (decodedData[j] !== expectedData[i][j]) {
+                            dataMatch = false;
+                            break;
+                        }
+                    }
+                    if (dataMatch) {
+                        console.log(`✅ Payload ${i + 1}: Data integrity verified`);
+                    } else {
+                        console.log(`❌ Payload ${i + 1}: Data integrity mismatch`);
+                        passed = false;
+                    }
+                }
+            } else if (expectedTypes[i] === 'table') {
+                const decodedData = Buffer.from(payload.data, 'base64');
+                if (decodedData.length > 0) {
+                    console.log(`✅ Payload ${i + 1}: Arrow IPC data present (${decodedData.length} bytes)`);
+                } else {
+                    console.log(`❌ Payload ${i + 1}: Arrow IPC data is empty`);
+                    passed = false;
+                }
+            }
+            
+            console.log(`   Size: ${payload.size} bytes\n`);
+        }
+        
+        // Test with chat-like payload (text + image + audio)
+        console.log('=== Chat-like Payload Test ===');
+        const chatData = [
+            ['text', 'Hello!', 'text'],
+            ['image', Buffer.from([0xFF, 0xD8, 0xFF, 0xE0]), 'image'],
+            ['audio', Buffer.from([0x46, 0x4C, 0x41, 0x43]), 'audio']
+        ];
+        
+        const [chatEnv, _] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            chatData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: 'chat-' + correlationId,
+                is_publish: false
+            }
+        );
+        
+        if (chatEnv.payloads.length === 3) {
+            console.log('✅ Chat-like payloads handled correctly');
+        } else {
+            console.log('❌ Chat-like payloads handling failed');
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_table_receiver.js

@@ -0,0 +1,173 @@
+/**
+ * JavaScript Table Receiver Test
+ * Tests the smartreceive function with table (Arrow IPC) payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Table Receiver Test ===\n');
+    
+    // Create a mock NATS message with table payload
+    const tableData = [
+        { id: 1, name: 'Alice', age: 30, active: true },
+        { id: 2, name: 'Bob', age: 25, active: false },
+        { id: 3, name: 'Charlie', age: 35, active: true }
+    ];
+    
+    // Convert to Arrow IPC format
+    const arrow = require('apache-arrow');
+    const fields = [
+        new arrow.Field('id', arrow.Int64, true),
+        new arrow.Field('name', arrow.Utf8, true),
+        new arrow.Field('age', arrow.Int64, true),
+        new arrow.Field('active', arrow.Boolean, true)
+    ];
+    const schema = new arrow.Schema(fields);
+    const batches = [];
+    for (const row of tableData) {
+        const batch = arrow.recordBatch.fromObjects([row], schema);
+        batches.push(batch);
+    }
+    const buffers = arrow.ipc.recordBatchesToMessage(batches, schema).buffers;
+    const combined = new Uint8Array(buffers.reduce((acc, b) => acc + b.byteLength, 0));
+    let offset = 0;
+    for (const buf of buffers) {
+        combined.set(new Uint8Array(buf), offset);
+        offset += buf.byteLength;
+    }
+    const arrowBuffer = Buffer.from(combined);
+    
+    const testData = {
+        correlation_id: 'js-table-receiver-' + crypto.randomUUID(),
+        msg_id: 'msg-' + crypto.randomUUID(),
+        timestamp: new Date().toISOString(),
+        send_to: '/test/table',
+        msg_purpose: 'test',
+        sender_name: 'js-table-test',
+        sender_id: 'sender-' + crypto.randomUUID(),
+        receiver_name: 'js-receiver',
+        receiver_id: 'receiver-' + crypto.randomUUID(),
+        reply_to: '',
+        reply_to_msg_id: '',
+        broker_url: TEST_BROKER_URL,
+        metadata: {},
+        payloads: [
+            {
+                id: 'payload-1',
+                dataname: 'users_table',
+                payload_type: 'table',
+                transport: 'direct',
+                encoding: 'base64',
+                size: arrowBuffer.length,
+                data: arrowBuffer.toString('base64'),
+                metadata: { payload_bytes: arrowBuffer.length }
+            }
+        ]
+    };
+    
+    const mockMsg = {
+        payload: JSON.stringify(testData)
+    };
+    
+    console.log('Mock Message Created:');
+    console.log(`  Correlation ID: ${testData.correlation_id}`);
+    console.log(`  Payloads: ${testData.payloads.length}`);
+    console.log(`  Payload type: ${testData.payloads[0].payload_type}`);
+    console.log(`  Transport: ${testData.payloads[0].transport}\n`);
+    
+    try {
+        // Receive and process the message
+        console.log('Receiving and processing message...');
+        const env = await NATSBridge.smartreceive(
+            mockMsg,
+            {
+                max_retries: 3,
+                base_delay: 100,
+                max_delay: 1000
+            }
+        );
+        
+        console.log('\n=== Received Envelope ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate received data
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (!env.correlation_id) {
+            console.log('❌ correlation_id is missing');
+            passed = false;
+        } else {
+            console.log('✅ correlation_id present');
+        }
+        
+        if (env.payloads.length !== 1) {
+            console.log(`❌ Expected 1 payload, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        const payload = env.payloads[0];
+        if (payload[0] !== 'users_table') {
+            console.log(`❌ Expected dataname 'users_table', got '${payload[0]}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct dataname');
+        }
+        
+        if (payload[2] !== 'table') {
+            console.log(`❌ Expected type 'table', got '${payload[2]}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct type');
+        }
+        
+        // Verify table data is a Buffer (Arrow IPC format)
+        if (payload[1] instanceof Buffer || payload[1] instanceof Uint8Array) {
+            console.log('✅ Table data is Arrow IPC buffer');
+            console.log(`   Buffer size: ${payload[1].length} bytes`);
+        } else {
+            console.log(`❌ Expected Buffer/Uint8Array, got ${typeof payload[1]}`);
+            passed = false;
+        }
+        
+        // Test round-trip with Arrow deserialization
+        console.log('\n=== Arrow Deserialization Test ===');
+        try {
+            const table = arrow.tableFromRawBytes(payload[1]);
+            console.log(`✅ Arrow table deserialized successfully`);
+            console.log(`   Schema: ${table.schema.fields.map(f => f.name).join(', ')}`);
+            console.log(`   Num rows: ${table.numRows}`);
+        } catch (e) {
+            console.log('❌ Arrow deserialization failed:', e.message);
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_table_sender.js

@@ -0,0 +1,180 @@
+/**
+ * JavaScript Table Sender Test
+ * Tests the smartsend function with table (Arrow IPC) payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_SUBJECT = '/test/table';
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Table Sender Test ===\n');
+    
+    const correlationId = crypto.randomUUID();
+    console.log(`Correlation ID: ${correlationId}`);
+    console.log(`Subject: ${TEST_SUBJECT}`);
+    console.log(`Broker URL: ${TEST_BROKER_URL}\n`);
+    
+    // Test data - table data as array of objects
+    const tableData = [
+        { id: 1, name: 'Alice', age: 30, active: true },
+        { id: 2, name: 'Bob', age: 25, active: false },
+        { id: 3, name: 'Charlie', age: 35, active: true },
+        { id: 4, name: 'Diana', age: 28, active: true },
+        { id: 5, name: 'Eve', age: 32, active: false }
+    ];
+    
+    const testData = [
+        ['users_table', tableData, 'table']
+    ];
+    
+    try {
+        // Send the message
+        console.log('Sending table payload...');
+        const [env, envJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            testData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: correlationId,
+                msg_purpose: 'test',
+                sender_name: 'js-table-test',
+                is_publish: false
+            }
+        );
+        
+        console.log('\n=== Envelope Created ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Purpose: ${env.msg_purpose}`);
+        console.log(`Sender: ${env.sender_name}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate envelope structure
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (env.payloads.length !== 1) {
+            console.log(`❌ Expected 1 payload, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        const payload = env.payloads[0];
+        if (payload.dataname !== 'users_table') {
+            console.log(`❌ Expected dataname 'users_table', got '${payload.dataname}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct dataname');
+        }
+        
+        if (payload.payload_type !== 'table') {
+            console.log(`❌ Expected payload_type 'table', got '${payload.payload_type}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct payload_type');
+        }
+        
+        if (payload.transport !== 'direct') {
+            console.log(`❌ Expected transport 'direct', got '${payload.transport}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct transport');
+        }
+        
+        if (payload.encoding !== 'base64') {
+            console.log(`❌ Expected encoding 'base64', got '${payload.encoding}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct encoding');
+        }
+        
+        // Verify Arrow IPC data can be decoded
+        console.log('\n=== Arrow IPC Verification ===');
+        const decodedData = Buffer.from(payload.data, 'base64');
+        console.log(`Arrow IPC buffer size: ${decodedData.length} bytes`);
+        
+        if (decodedData.length > 0) {
+            console.log('✅ Arrow IPC data present');
+        } else {
+            console.log('❌ Arrow IPC data is empty');
+            passed = false;
+        }
+        
+        // Test with larger table
+        console.log('\n=== Larger Table Test ===');
+        const largeTableData = [];
+        for (let i = 1; i <= 100; i++) {
+            largeTableData.push({
+                id: i,
+                name: `User${i}`,
+                age: Math.floor(Math.random() * 100),
+                active: Math.random() > 0.5,
+                score: Math.random() * 100
+            });
+        }
+        
+        const largeTestData = [
+            ['large_table', largeTableData, 'table']
+        ];
+        
+        const [largeEnv, _] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            largeTestData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: 'large-' + correlationId,
+                is_publish: false
+            }
+        );
+        
+        if (largeEnv.payloads.length === 1) {
+            console.log('✅ Large table handled correctly');
+            console.log(`   Size: ${largeEnv.payloads[0].size} bytes`);
+        } else {
+            console.log('❌ Large table handling failed');
+            passed = false;
+        }
+        
+        // Test JSON string output
+        console.log('\n=== JSON String Output Test ===');
+        try {
+            const parsed = JSON.parse(envJsonStr);
+            if (parsed.correlation_id === env.correlation_id && 
+                parsed.payloads.length === env.payloads.length) {
+                console.log('✅ JSON string is valid and matches envelope');
+            } else {
+                console.log('❌ JSON string does not match envelope');
+                passed = false;
+            }
+        } catch (e) {
+            console.log('❌ JSON string is invalid:', e.message);
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_text_receiver.js

@@ -0,0 +1,207 @@
+/**
+ * JavaScript Text Receiver Test
+ * Tests the smartreceive function with text payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Text Receiver Test ===\n');
+    
+    // Create a mock NATS message with text payload
+    const testData = {
+        correlation_id: 'test-receiver-' + crypto.randomUUID(),
+        msg_id: 'msg-' + crypto.randomUUID(),
+        timestamp: new Date().toISOString(),
+        send_to: '/test/text',
+        msg_purpose: 'test',
+        sender_name: 'js-text-test',
+        sender_id: 'sender-' + crypto.randomUUID(),
+        receiver_name: 'js-receiver',
+        receiver_id: 'receiver-' + crypto.randomUUID(),
+        reply_to: '',
+        reply_to_msg_id: '',
+        broker_url: TEST_BROKER_URL,
+        metadata: {},
+        payloads: [
+            {
+                id: 'payload-' + crypto.randomUUID(),
+                dataname: 'message',
+                payload_type: 'text',
+                transport: 'direct',
+                encoding: 'base64',
+                size: 38,
+                data: Buffer.from('Hello, NATSBridge! This is a test message.').toString('base64'),
+                metadata: { payload_bytes: 38 }
+            }
+        ]
+    };
+    
+    const mockMsg = {
+        payload: JSON.stringify(testData)
+    };
+    
+    console.log('Mock Message Created:');
+    console.log(`  Correlation ID: ${testData.correlation_id}`);
+    console.log(`  Payloads: ${testData.payloads.length}`);
+    console.log(`  Payload dataname: ${testData.payloads[0].dataname}`);
+    console.log(`  Payload type: ${testData.payloads[0].payload_type}`);
+    console.log(`  Transport: ${testData.payloads[0].transport}\n`);
+    
+    try {
+        // Receive and process the message
+        console.log('Receiving and processing message...');
+        const env = await NATSBridge.smartreceive(
+            mockMsg,
+            {
+                max_retries: 3,
+                base_delay: 100,
+                max_delay: 1000
+            }
+        );
+        
+        console.log('\n=== Received Envelope ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate received data
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (!env.correlation_id) {
+            console.log('❌ correlation_id is missing');
+            passed = false;
+        } else {
+            console.log('✅ correlation_id present');
+        }
+        
+        if (env.payloads.length !== 1) {
+            console.log(`❌ Expected 1 payload, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        const payload = env.payloads[0];
+        if (payload[0] !== 'message') {
+            console.log(`❌ Expected dataname 'message', got '${payload[0]}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct dataname');
+        }
+        
+        if (payload[2] !== 'text') {
+            console.log(`❌ Expected type 'text', got '${payload[2]}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct type');
+        }
+        
+        if (payload[1] !== 'Hello, NATSBridge! This is a test message.') {
+            console.log(`❌ Data mismatch`);
+            console.log(`   Expected: Hello, NATSBridge! This is a test message.`);
+            console.log(`   Got: ${payload[1]}`);
+            passed = false;
+        } else {
+            console.log('✅ Data correctly deserialized');
+        }
+        
+        // Test with multiple text payloads
+        console.log('\n=== Multiple Text Payloads Test ===');
+        const multiTestData = {
+            correlation_id: 'multi-receiver-' + crypto.randomUUID(),
+            msg_id: 'msg-' + crypto.randomUUID(),
+            timestamp: new Date().toISOString(),
+            send_to: '/test/text',
+            msg_purpose: 'test',
+            sender_name: 'js-text-test',
+            sender_id: 'sender-' + crypto.randomUUID(),
+            receiver_name: 'js-receiver',
+            receiver_id: 'receiver-' + crypto.randomUUID(),
+            reply_to: '',
+            reply_to_msg_id: '',
+            broker_url: TEST_BROKER_URL,
+            metadata: {},
+            payloads: [
+                {
+                    id: 'payload-1',
+                    dataname: 'msg1',
+                    payload_type: 'text',
+                    transport: 'direct',
+                    encoding: 'base64',
+                    size: 16,
+                    data: Buffer.from('First message').toString('base64'),
+                    metadata: { payload_bytes: 16 }
+                },
+                {
+                    id: 'payload-2',
+                    dataname: 'msg2',
+                    payload_type: 'text',
+                    transport: 'direct',
+                    encoding: 'base64',
+                    size: 16,
+                    data: Buffer.from('Second message').toString('base64'),
+                    metadata: { payload_bytes: 16 }
+                },
+                {
+                    id: 'payload-3',
+                    dataname: 'msg3',
+                    payload_type: 'text',
+                    transport: 'direct',
+                    encoding: 'base64',
+                    size: 16,
+                    data: Buffer.from('Third message').toString('base64'),
+                    metadata: { payload_bytes: 16 }
+                }
+            ]
+        };
+        
+        const mockMultiMsg = {
+            payload: JSON.stringify(multiTestData)
+        };
+        
+        const multiEnv = await NATSBridge.smartreceive(mockMultiMsg);
+        
+        if (multiEnv.payloads.length === 3) {
+            console.log('✅ Multiple payloads handled correctly');
+            
+            // Verify each payload
+            const expectedMessages = ['First message', 'Second message', 'Third message'];
+            for (let i = 0; i < 3; i++) {
+                if (multiEnv.payloads[i][1] === expectedMessages[i]) {
+                    console.log(`✅ Payload ${i + 1} correctly deserialized`);
+                } else {
+                    console.log(`❌ Payload ${i + 1} mismatch`);
+                    passed = false;
+                }
+            }
+        } else {
+            console.log(`❌ Expected 3 payloads, got ${multiEnv.payloads.length}`);
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_js_text_sender.js

@@ -0,0 +1,170 @@
+/**
+ * JavaScript Text Sender Test
+ * Tests the smartsend function with text payloads
+ */
+
+const NATSBridge = require('../src/natsbridge.js');
+const crypto = require('crypto');
+
+const TEST_SUBJECT = '/test/text';
+const TEST_BROKER_URL = process.env.NATS_URL || 'nats://localhost:4222';
+const TEST_FILESERVER_URL = process.env.FILESERVER_URL || 'http://localhost:8080';
+
+async function runTest() {
+    console.log('=== JavaScript Text Sender Test ===\n');
+    
+    const correlationId = crypto.randomUUID();
+    console.log(`Correlation ID: ${correlationId}`);
+    console.log(`Subject: ${TEST_SUBJECT}`);
+    console.log(`Broker URL: ${TEST_BROKER_URL}\n`);
+    
+    // Test data
+    const textData = 'Hello, NATSBridge! This is a test message.';
+    const testData = [
+        ['message', textData, 'text']
+    ];
+    
+    try {
+        // Send the message
+        console.log('Sending text payload...');
+        const [env, envJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            testData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: correlationId,
+                msg_purpose: 'test',
+                sender_name: 'js-text-test',
+                is_publish: false  // Don't actually publish for this test
+            }
+        );
+        
+        console.log('\n=== Envelope Created ===');
+        console.log(`Correlation ID: ${env.correlation_id}`);
+        console.log(`Message ID: ${env.msg_id}`);
+        console.log(`Timestamp: ${env.timestamp}`);
+        console.log(`Subject: ${env.send_to}`);
+        console.log(`Purpose: ${env.msg_purpose}`);
+        console.log(`Sender: ${env.sender_name}`);
+        console.log(`Payloads: ${env.payloads.length}\n`);
+        
+        // Validate envelope structure
+        console.log('=== Validation ===');
+        let passed = true;
+        
+        if (!env.correlation_id) {
+            console.log('❌ correlation_id is missing');
+            passed = false;
+        } else {
+            console.log('✅ correlation_id present');
+        }
+        
+        if (!env.msg_id) {
+            console.log('❌ msg_id is missing');
+            passed = false;
+        } else {
+            console.log('✅ msg_id present');
+        }
+        
+        if (!env.timestamp) {
+            console.log('❌ timestamp is missing');
+            passed = false;
+        } else {
+            console.log('✅ timestamp present');
+        }
+        
+        if (env.payloads.length !== 1) {
+            console.log(`❌ Expected 1 payload, got ${env.payloads.length}`);
+            passed = false;
+        } else {
+            console.log('✅ Correct number of payloads');
+        }
+        
+        const payload = env.payloads[0];
+        if (payload.dataname !== 'message') {
+            console.log(`❌ Expected dataname 'message', got '${payload.dataname}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct dataname');
+        }
+        
+        if (payload.payload_type !== 'text') {
+            console.log(`❌ Expected payload_type 'text', got '${payload.payload_type}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct payload_type');
+        }
+        
+        if (payload.transport !== 'direct') {
+            console.log(`❌ Expected transport 'direct', got '${payload.transport}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct transport');
+        }
+        
+        if (payload.encoding !== 'base64') {
+            console.log(`❌ Expected encoding 'base64', got '${payload.encoding}'`);
+            passed = false;
+        } else {
+            console.log('✅ Correct encoding');
+        }
+        
+        // Decode and verify the data
+        const decodedData = Buffer.from(payload.data, 'base64').toString('utf8');
+        if (decodedData !== textData) {
+            console.log(`❌ Decoded data mismatch`);
+            console.log(`   Expected: ${textData}`);
+            console.log(`   Got: ${decodedData}`);
+            passed = false;
+        } else {
+            console.log('✅ Data integrity verified');
+        }
+        
+        console.log(`\nPayload size: ${payload.size} bytes`);
+        console.log(`Base64 data length: ${payload.data.length} chars`);
+        
+        // Test with multiple text payloads
+        console.log('\n=== Multiple Text Payloads Test ===');
+        const multiTestData = [
+            ['msg1', 'First message', 'text'],
+            ['msg2', 'Second message', 'text'],
+            ['msg3', 'Third message', 'text']
+        ];
+        
+        const [multiEnv, multiEnvJsonStr] = await NATSBridge.smartsend(
+            TEST_SUBJECT,
+            multiTestData,
+            {
+                broker_url: TEST_BROKER_URL,
+                fileserver_url: TEST_FILESERVER_URL,
+                correlation_id: 'multi-test-' + correlationId,
+                is_publish: false
+            }
+        );
+        
+        if (multiEnv.payloads.length === 3) {
+            console.log('✅ Multiple payloads handled correctly');
+        } else {
+            console.log(`❌ Expected 3 payloads, got ${multiEnv.payloads.length}`);
+            passed = false;
+        }
+        
+        // Final result
+        console.log('\n=== Test Result ===');
+        if (passed) {
+            console.log('✅ ALL TESTS PASSED');
+            process.exit(0);
+        } else {
+            console.log('❌ SOME TESTS FAILED');
+            process.exit(1);
+        }
+        
+    } catch (error) {
+        console.error('❌ Test failed with error:', error.message);
+        console.error(error.stack);
+        process.exit(1);
+    }
+}
+
+runTest();

test/test_julia_mix_payloads_sender.jl

@@ -186,7 +186,7 @@ function test_mix_send()
     ]
     
     # Use smartsend with mixed content
-    env, env_json_str = NATSBridge.smartsend(
+    sendinfo = NATSBridge.smartsend(
         SUBJECT,
         payloads;  # List of (dataname, data, type) tuples
         broker_url = NATS_URL,
@@ -202,7 +202,8 @@ function test_mix_send()
         reply_to_msg_id = "",
         is_publish = true  # Publish the message to NATS
     )
-    
+
+    env, env_json_str = sendinfo
     log_trace("Sent message with $(length(env.payloads)) payloads")
     
     # Log transport type for each payload

test/test_mpy_binary_receiver.py

@@ -0,0 +1,185 @@
+"""
+MicroPython Binary Receiver Test
+Tests the smartreceive function with binary/image/audio/video payloads
+
+Note: This test is designed for both MicroPython and desktop Python
+for compatibility testing.
+"""
+
+import sys
+import os
+import json
+import base64
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge_mpy import smartreceive, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+def run_test():
+    print('=== MicroPython Binary Receiver Test ===\n')
+    
+    from natsbridge_mpy import _generate_uuid
+    
+    # Create mock NATS message with binary payloads
+    image_data = bytes([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A])  # PNG header
+    audio_data = bytes([0x46, 0x4C, 0x41, 0x43, 0x00, 0x00, 0x00, 0x00])  # FLAC header
+    video_data = bytes([0x00, 0x00, 0x00, 0x18, 0x66, 0x74, 0x79, 0x70])  # MP4 header
+    generic_binary = bytes([0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE])
+    
+    test_data = {
+        'correlation_id': 'mpy-binary-receiver-' + _generate_uuid(),
+        'msg_id': _generate_uuid(),
+        'timestamp': '2024-01-15T10:30:00Z',
+        'send_to': '/test/binary',
+        'msg_purpose': 'test',
+        'sender_name': 'mpy-binary-test',
+        'sender_id': _generate_uuid(),
+        'receiver_name': 'mpy-receiver',
+        'receiver_id': _generate_uuid(),
+        'reply_to': '',
+        'reply_to_msg_id': '',
+        'broker_url': TEST_BROKER_URL,
+        'metadata': {},
+        'payloads': [
+            {
+                'id': _generate_uuid(),
+                'dataname': 'image',
+                'payload_type': 'image',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(image_data),
+                'data': base64.b64encode(image_data).decode('ascii'),
+                'metadata': {'payload_bytes': len(image_data)}
+            },
+            {
+                'id': _generate_uuid(),
+                'dataname': 'audio',
+                'payload_type': 'audio',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(audio_data),
+                'data': base64.b64encode(audio_data).decode('ascii'),
+                'metadata': {'payload_bytes': len(audio_data)}
+            },
+            {
+                'id': _generate_uuid(),
+                'dataname': 'video',
+                'payload_type': 'video',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(video_data),
+                'data': base64.b64encode(video_data).decode('ascii'),
+                'metadata': {'payload_bytes': len(video_data)}
+            },
+            {
+                'id': _generate_uuid(),
+                'dataname': 'binary',
+                'payload_type': 'binary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(generic_binary),
+                'data': base64.b64encode(generic_binary).decode('ascii'),
+                'metadata': {'payload_bytes': len(generic_binary)}
+            }
+        ]
+    }
+    
+    mock_msg = {
+        'payload': json.dumps(test_data)
+    }
+    
+    print('Mock Message Created:')
+    print(f'  Correlation ID: {test_data["correlation_id"]}')
+    print(f'  Payloads: {len(test_data["payloads"])}')
+    print(f'  Payload types: {", ".join(p["payload_type"] for p in test_data["payloads"])}\n')
+    
+    try:
+        # Receive and process the message
+        print('Receiving and processing message...')
+        env = smartreceive(
+            mock_msg,
+            max_retries=3,
+            base_delay=100,
+            max_delay=1000
+        )
+        
+        print('\n=== Received Envelope ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate received data
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Expected data
+        expected_data = [
+            ('image', image_data, 'image'),
+            ('audio', audio_data, 'audio'),
+            ('video', video_data, 'video'),
+            ('binary', generic_binary, 'binary')
+        ]
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            expected = expected_data[i]
+            
+            if payload[0] != expected[0]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected[0]}', got '{payload[0]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload[2] != expected[2]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected[2]}', got '{payload[2]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            # Verify binary data integrity
+            received_data = payload[1]
+            if received_data != expected[1]:
+                print(f'❌ Payload {i + 1}: Data mismatch')
+                print(f'   Expected: {expected[1]}')
+                print(f'   Got: {received_data}')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data correctly deserialized')
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    run_test()

test/test_mpy_binary_sender.py

@@ -0,0 +1,163 @@
+"""
+MicroPython Binary Sender Test
+Tests the smartsend function with binary/image/audio/video payloads
+
+Note: This test is designed for both MicroPython and desktop Python
+for compatibility testing.
+"""
+
+import sys
+import os
+import base64
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge_mpy import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL, DEFAULT_SIZE_THRESHOLD, MAX_PAYLOAD_SIZE
+
+TEST_SUBJECT = '/test/binary'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+def run_test():
+    print('=== MicroPython Binary Sender Test ===\n')
+    
+    from natsbridge_mpy import _generate_uuid
+    correlation_id = 'mpy-binary-test-' + _generate_uuid()
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}')
+    print(f'Default Size Threshold: {DEFAULT_SIZE_THRESHOLD} bytes')
+    print(f'Max Payload Size: {MAX_PAYLOAD_SIZE} bytes\n')
+    
+    # Test data - binary data for different types
+    image_data = bytearray([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A])  # PNG header
+    audio_data = bytearray([0x46, 0x4C, 0x41, 0x43, 0x00, 0x00, 0x00, 0x00])  # FLAC header
+    video_data = bytearray([0x00, 0x00, 0x00, 0x18, 0x66, 0x74, 0x79, 0x70])  # MP4 header
+    generic_binary = bytearray([0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE])
+    
+    test_data = [
+        ('image', bytes(image_data), 'image'),
+        ('audio', bytes(audio_data), 'audio'),
+        ('video', bytes(video_data), 'video'),
+        ('binary', bytes(generic_binary), 'binary')
+    ]
+    
+    try:
+        # Send the message
+        print('Sending binary payloads...')
+        env, env_json_str = smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='mpy-binary-test',
+            is_publish=False
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Test each payload
+        expected_datanames = ['image', 'audio', 'video', 'binary']
+        expected_types = ['image', 'audio', 'video', 'binary']
+        expected_data = [bytes(image_data), bytes(audio_data), bytes(video_data), bytes(generic_binary)]
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            
+            if payload['dataname'] != expected_datanames[i]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected_datanames[i]}', got '{payload['dataname']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload['payload_type'] != expected_types[i]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected_types[i]}', got '{payload['payload_type']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            if payload['transport'] != 'direct':
+                print(f"❌ Payload {i + 1}: Expected transport 'direct', got '{payload['transport']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct transport')
+            
+            if payload['encoding'] != 'base64':
+                print(f"❌ Payload {i + 1}: Expected encoding 'base64', got '{payload['encoding']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct encoding')
+            
+            # Decode and verify the data
+            decoded_data = base64.b64decode(payload['data'])
+            original_data = expected_data[i]
+            
+            if decoded_data != original_data:
+                print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data integrity verified')
+            
+            print(f'   Size: {payload["size"]} bytes\n')
+        
+        # Test with larger binary data
+        print('=== Large Binary Data Test ===')
+        large_data = bytes([0xFF] * 1000)  # 1KB of binary data
+        large_test_data = [
+            ('large_binary', large_data, 'binary')
+        ]
+        
+        large_env, _ = smartsend(
+            TEST_SUBJECT,
+            large_test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='large-' + correlation_id,
+            is_publish=False
+        )
+        
+        if len(large_env['payloads']) == 1 and large_env['payloads'][0]['size'] == 1000:
+            print('✅ Large binary data handled correctly')
+        else:
+            print('❌ Large binary data handling failed')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    run_test()

test/test_mpy_dictionary_receiver.py

@@ -0,0 +1,224 @@
+"""
+MicroPython Dictionary Receiver Test
+Tests the smartreceive function with dictionary payloads
+
+Note: This test is designed for both MicroPython and desktop Python
+for compatibility testing.
+"""
+
+import sys
+import os
+import json
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge_mpy import smartreceive, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+def run_test():
+    print('=== MicroPython Dictionary Receiver Test ===\n')
+    
+    from natsbridge_mpy import _generate_uuid
+    
+    # Create a mock NATS message with dictionary payloads
+    import base64
+    
+    simple_dict = {'key1': 'value1', 'key2': 'value2'}
+    nested_dict = {'outer': {'inner': 'value', 'number': 42}}
+    array_dict = {'items': [1, 2, 3, 'four', 'five']}
+    mixed_dict = {'string': 'text', 'number': 123, 'boolean': True, 'null_val': None}
+    
+    test_data = {
+        'correlation_id': 'mpy-receiver-dict-' + _generate_uuid(),
+        'msg_id': _generate_uuid(),
+        'timestamp': '2024-01-15T10:30:00Z',
+        'send_to': '/test/dictionary',
+        'msg_purpose': 'test',
+        'sender_name': 'mpy-dict-test',
+        'sender_id': _generate_uuid(),
+        'receiver_name': 'mpy-receiver',
+        'receiver_id': _generate_uuid(),
+        'reply_to': '',
+        'reply_to_msg_id': '',
+        'broker_url': TEST_BROKER_URL,
+        'metadata': {},
+        'payloads': [
+            {
+                'id': _generate_uuid(),
+                'dataname': 'simple_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(simple_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(simple_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(simple_dict).encode('utf8'))}
+            },
+            {
+                'id': _generate_uuid(),
+                'dataname': 'nested_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(nested_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(nested_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(nested_dict).encode('utf8'))}
+            },
+            {
+                'id': _generate_uuid(),
+                'dataname': 'array_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(array_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(array_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(array_dict).encode('utf8'))}
+            },
+            {
+                'id': _generate_uuid(),
+                'dataname': 'mixed_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(mixed_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(mixed_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(mixed_dict).encode('utf8'))}
+            }
+        ]
+    }
+    
+    mock_msg = {
+        'payload': json.dumps(test_data)
+    }
+    
+    print('Mock Message Created:')
+    print(f'  Correlation ID: {test_data["correlation_id"]}')
+    print(f'  Payloads: {len(test_data["payloads"])}')
+    print(f'  Payload types: {", ".join(p["payload_type"] for p in test_data["payloads"])}\n')
+    
+    try:
+        # Receive and process the message
+        print('Receiving and processing message...')
+        env = smartreceive(
+            mock_msg,
+            max_retries=3,
+            base_delay=100,
+            max_delay=1000
+        )
+        
+        print('\n=== Received Envelope ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate received data
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Expected data
+        expected_data = [
+            ('simple_dict', simple_dict, 'dictionary'),
+            ('nested_dict', nested_dict, 'dictionary'),
+            ('array_dict', array_dict, 'dictionary'),
+            ('mixed_dict', mixed_dict, 'dictionary')
+        ]
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            expected = expected_data[i]
+            
+            if payload[0] != expected[0]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected[0]}', got '{payload[0]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload[2] != expected[2]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected[2]}', got '{payload[2]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            data_match = json.dumps(payload[1], sort_keys=True) == json.dumps(expected[1], sort_keys=True)
+            if not data_match:
+                print(f'❌ Payload {i + 1}: Data mismatch')
+                print(f'   Expected: {json.dumps(expected[1], sort_keys=True)}')
+                print(f'   Got: {json.dumps(payload[1], sort_keys=True)}')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data correctly deserialized')
+        
+        # Test round-trip with receive
+        print('\n=== Round-trip Test ===')
+        round_trip_data = {
+            'correlation_id': 'roundtrip-' + _generate_uuid(),
+            'msg_id': _generate_uuid(),
+            'timestamp': '2024-01-15T10:30:00Z',
+            'send_to': '/test/dictionary',
+            'msg_purpose': 'test',
+            'sender_name': 'mpy-test',
+            'sender_id': _generate_uuid(),
+            'receiver_name': 'mpy-receiver',
+            'receiver_id': _generate_uuid(),
+            'reply_to': '',
+            'reply_to_msg_id': '',
+            'broker_url': TEST_BROKER_URL,
+            'metadata': {},
+            'payloads': [
+                {
+                    'id': _generate_uuid(),
+                    'dataname': 'roundtrip',
+                    'payload_type': 'dictionary',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': len(json.dumps({'test': 'data', 'nested': {'a': 1, 'b': 2}}).encode('utf8')),
+                    'data': base64.b64encode(json.dumps({'test': 'data', 'nested': {'a': 1, 'b': 2}}).encode('utf8')).decode('ascii'),
+                    'metadata': {'payload_bytes': len(json.dumps({'test': 'data', 'nested': {'a': 1, 'b': 2}}).encode('utf8'))}
+                }
+            ]
+        }
+        
+        mock_rt_msg = {'payload': json.dumps(round_trip_data)}
+        rt_env = smartreceive(mock_rt_msg)
+        
+        if rt_env['payloads'][0][0] == 'roundtrip' and rt_env['payloads'][0][2] == 'dictionary':
+            print('✅ Round-trip test successful')
+        else:
+            print('❌ Round-trip test failed')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    run_test()

test/test_mpy_dictionary_sender.py

@@ -0,0 +1,177 @@
+"""
+MicroPython Dictionary Sender Test
+Tests the smartsend function with dictionary payloads
+
+Note: This test is designed for both MicroPython and desktop Python
+for compatibility testing.
+"""
+
+import sys
+import os
+import json
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge_mpy import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL, DEFAULT_SIZE_THRESHOLD, MAX_PAYLOAD_SIZE
+
+TEST_SUBJECT = '/test/dictionary'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+def run_test():
+    print('=== MicroPython Dictionary Sender Test ===\n')
+    
+    from natsbridge_mpy import _generate_uuid
+    correlation_id = 'mpy-dict-test-' + _generate_uuid()
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}')
+    print(f'Default Size Threshold: {DEFAULT_SIZE_THRESHOLD} bytes')
+    print(f'Max Payload Size: {MAX_PAYLOAD_SIZE} bytes\n')
+    
+    # Test data - various dictionary structures
+    test_data = [
+        ('simple_dict', {'key1': 'value1', 'key2': 'value2'}, 'dictionary'),
+        ('nested_dict', {'outer': {'inner': 'value', 'number': 42}}, 'dictionary'),
+        ('array_dict', {'items': [1, 2, 3, 'four', 'five']}, 'dictionary'),
+        ('mixed_dict', {'string': 'text', 'number': 123, 'boolean': True, 'null_val': None}, 'dictionary')
+    ]
+    
+    try:
+        # Send the message
+        print('Sending dictionary payloads...')
+        env, env_json_str = smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='mpy-dict-test',
+            is_publish=False
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Test each payload
+        expected_datanames = ['simple_dict', 'nested_dict', 'array_dict', 'mixed_dict']
+        expected_types = ['dictionary', 'dictionary', 'dictionary', 'dictionary']
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            
+            if payload['dataname'] != expected_datanames[i]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected_datanames[i]}', got '{payload['dataname']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload['payload_type'] != expected_types[i]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected_types[i]}', got '{payload['payload_type']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            if payload['transport'] != 'direct':
+                print(f"❌ Payload {i + 1}: Expected transport 'direct', got '{payload['transport']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct transport')
+            
+            if payload['encoding'] != 'base64':
+                print(f"❌ Payload {i + 1}: Expected encoding 'base64', got '{payload['encoding']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct encoding')
+            
+            # Decode and verify the data
+            import base64
+            decoded_data = json.loads(base64.b64decode(payload['data']).decode('ascii'))
+            original_data = test_data[i][1]
+            
+            # Normalize for comparison
+            if json.dumps(decoded_data, sort_keys=True) != json.dumps(original_data, sort_keys=True):
+                print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                print(f'   Expected: {json.dumps(original_data)}')
+                print(f'   Got: {json.dumps(decoded_data)}')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data integrity verified')
+            
+            print(f'   Size: {payload["size"]} bytes\n')
+        
+        # Test round-trip serialization
+        print('=== Round-trip Serialization Test ===')
+        round_trip_data = [
+            ('roundtrip', {'test': 'data', 'numbers': [1, 2, 3], 'nested': {'a': 1, 'b': 2}}, 'dictionary')
+        ]
+        
+        rt_env, _ = smartsend(
+            TEST_SUBJECT,
+            round_trip_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='roundtrip-' + correlation_id,
+            is_publish=False
+        )
+        
+        rt_payload = rt_env['payloads'][0]
+        rt_decoded = json.loads(base64.b64decode(rt_payload['data']).decode('ascii'))
+        
+        if json.dumps(rt_decoded, sort_keys=True) == json.dumps(round_trip_data[0][1], sort_keys=True):
+            print('✅ Round-trip serialization successful')
+        else:
+            print('❌ Round-trip serialization failed')
+            passed = False
+        
+        # Test JSON string output
+        print('\n=== JSON String Output Test ===')
+        try:
+            parsed = json.loads(env_json_str)
+            if parsed['correlation_id'] == env['correlation_id'] and \
+               len(parsed['payloads']) == len(env['payloads']):
+                print('✅ JSON string is valid and matches envelope')
+            else:
+                print('❌ JSON string does not match envelope')
+                passed = False
+        except json.JSONDecodeError as e:
+            print(f'❌ JSON string is invalid: {e}')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    run_test()

test/test_mpy_text_receiver.py

@@ -0,0 +1,209 @@
+"""
+MicroPython Text Receiver Test
+Tests the smartreceive function with text payloads
+
+Note: This test is designed for both MicroPython and desktop Python
+for compatibility testing.
+"""
+
+import sys
+import os
+import json
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge_mpy import smartreceive, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+def run_test():
+    print('=== MicroPython Text Receiver Test ===\n')
+    
+    from natsbridge_mpy import _generate_uuid
+    
+    # Create a mock NATS message with text payload
+    test_text = 'Hello, NATSBridge! This is a test message.'
+    import base64
+    
+    test_data = {
+        'correlation_id': 'mpy-receiver-test-' + _generate_uuid(),
+        'msg_id': _generate_uuid(),
+        'timestamp': '2024-01-15T10:30:00Z',
+        'send_to': '/test/text',
+        'msg_purpose': 'test',
+        'sender_name': 'mpy-text-test',
+        'sender_id': _generate_uuid(),
+        'receiver_name': 'mpy-receiver',
+        'receiver_id': _generate_uuid(),
+        'reply_to': '',
+        'reply_to_msg_id': '',
+        'broker_url': TEST_BROKER_URL,
+        'metadata': {},
+        'payloads': [
+            {
+                'id': _generate_uuid(),
+                'dataname': 'message',
+                'payload_type': 'text',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(test_text.encode('utf8')),
+                'data': base64.b64encode(test_text.encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(test_text.encode('utf8'))}
+            }
+        ]
+    }
+    
+    mock_msg = {
+        'payload': json.dumps(test_data)
+    }
+    
+    print('Mock Message Created:')
+    print(f'  Correlation ID: {test_data["correlation_id"]}')
+    print(f'  Payloads: {len(test_data["payloads"])}')
+    print(f'  Payload dataname: {test_data["payloads"][0]["dataname"]}')
+    print(f'  Payload type: {test_data["payloads"][0]["payload_type"]}')
+    print(f'  Transport: {test_data["payloads"][0]["transport"]}\n')
+    
+    try:
+        # Receive and process the message
+        print('Receiving and processing message...')
+        env = smartreceive(
+            mock_msg,
+            max_retries=3,
+            base_delay=100,
+            max_delay=1000
+        )
+        
+        print('\n=== Received Envelope ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate received data
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if len(env['payloads']) != 1:
+            print(f'❌ Expected 1 payload, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        payload = env['payloads'][0]
+        if payload[0] != 'message':
+            print(f"❌ Expected dataname 'message', got '{payload[0]}'")
+            passed = False
+        else:
+            print('✅ Correct dataname')
+        
+        if payload[2] != 'text':
+            print(f"❌ Expected type 'text', got '{payload[2]}'")
+            passed = False
+        else:
+            print('✅ Correct type')
+        
+        if payload[1] != test_text:
+            print('❌ Data mismatch')
+            print(f'   Expected: {test_text}')
+            print(f'   Got: {payload[1]}')
+            passed = False
+        else:
+            print('✅ Data correctly deserialized')
+        
+        # Test with multiple text payloads
+        print('\n=== Multiple Text Payloads Test ===')
+        multi_test_data = {
+            'correlation_id': 'multi-receiver-' + _generate_uuid(),
+            'msg_id': _generate_uuid(),
+            'timestamp': '2024-01-15T10:30:00Z',
+            'send_to': '/test/text',
+            'msg_purpose': 'test',
+            'sender_name': 'mpy-text-test',
+            'sender_id': _generate_uuid(),
+            'receiver_name': 'mpy-receiver',
+            'receiver_id': _generate_uuid(),
+            'reply_to': '',
+            'reply_to_msg_id': '',
+            'broker_url': TEST_BROKER_URL,
+            'metadata': {},
+            'payloads': [
+                {
+                    'id': _generate_uuid(),
+                    'dataname': 'msg1',
+                    'payload_type': 'text',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': 16,
+                    'data': base64.b64encode(b'First message').decode('ascii'),
+                    'metadata': {'payload_bytes': 16}
+                },
+                {
+                    'id': _generate_uuid(),
+                    'dataname': 'msg2',
+                    'payload_type': 'text',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': 16,
+                    'data': base64.b64encode(b'Second message').decode('ascii'),
+                    'metadata': {'payload_bytes': 16}
+                },
+                {
+                    'id': _generate_uuid(),
+                    'dataname': 'msg3',
+                    'payload_type': 'text',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': 16,
+                    'data': base64.b64encode(b'Third message').decode('ascii'),
+                    'metadata': {'payload_bytes': 16}
+                }
+            ]
+        }
+        
+        mock_multi_msg = {'payload': json.dumps(multi_test_data)}
+        multi_env = smartreceive(mock_multi_msg)
+        
+        if len(multi_env['payloads']) == 3:
+            print('✅ Multiple payloads handled correctly')
+            
+            # Verify each payload
+            expected_messages = ['First message', 'Second message', 'Third message']
+            for i in range(3):
+                if multi_env['payloads'][i][1] == expected_messages[i]:
+                    print(f'✅ Payload {i + 1} correctly deserialized')
+                else:
+                    print(f'❌ Payload {i + 1} mismatch')
+                    passed = False
+        else:
+            print(f'❌ Expected 3 payloads, got {len(multi_env["payloads"])}')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    run_test()

test/test_mpy_text_sender.py

@@ -0,0 +1,205 @@
+"""
+MicroPython Text Sender Test
+Tests the smartsend function with text payloads
+
+Note: This test is designed for both MicroPython and desktop Python
+for compatibility testing.
+"""
+
+import sys
+import os
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge_mpy import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL, DEFAULT_SIZE_THRESHOLD, MAX_PAYLOAD_SIZE
+
+TEST_SUBJECT = '/test/text'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+def run_test():
+    print('=== MicroPython Text Sender Test ===\n')
+    
+    from natsbridge_mpy import _generate_uuid
+    correlation_id = 'mpy-text-test-' + _generate_uuid()
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}')
+    print(f'Default Size Threshold: {DEFAULT_SIZE_THRESHOLD} bytes')
+    print(f'Max Payload Size: {MAX_PAYLOAD_SIZE} bytes\n')
+    
+    # Test data
+    text_data = 'Hello, NATSBridge! This is a test message.'
+    test_data = [
+        ('message', text_data, 'text')
+    ]
+    
+    try:
+        # Send the message
+        print('Sending text payload...')
+        env, env_json_str = smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='mpy-text-test',
+            is_publish=False  # Don't actually publish for this test
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if not env.get('msg_id'):
+            print('❌ msg_id is missing')
+            passed = False
+        else:
+            print('✅ msg_id present')
+        
+        if not env.get('timestamp'):
+            print('❌ timestamp is missing')
+            passed = False
+        else:
+            print('✅ timestamp present')
+        
+        if len(env['payloads']) != 1:
+            print(f'❌ Expected 1 payload, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        payload = env['payloads'][0]
+        if payload['dataname'] != 'message':
+            print(f"❌ Expected dataname 'message', got '{payload['dataname']}'")
+            passed = False
+        else:
+            print('✅ Correct dataname')
+        
+        if payload['payload_type'] != 'text':
+            print(f"❌ Expected payload_type 'text', got '{payload['payload_type']}'")
+            passed = False
+        else:
+            print('✅ Correct payload_type')
+        
+        if payload['transport'] != 'direct':
+            print(f"❌ Expected transport 'direct', got '{payload['transport']}'")
+            passed = False
+        else:
+            print('✅ Correct transport')
+        
+        if payload['encoding'] != 'base64':
+            print(f"❌ Expected encoding 'base64', got '{payload['encoding']}'")
+            passed = False
+        else:
+            print('✅ Correct encoding')
+        
+        # Decode and verify the data
+        import base64
+        decoded_data = base64.b64decode(payload['data']).decode('ascii')
+        if decoded_data != text_data:
+            print('❌ Decoded data mismatch')
+            print(f'   Expected: {text_data}')
+            print(f'   Got: {decoded_data}')
+            passed = False
+        else:
+            print('✅ Data integrity verified')
+        
+        print(f'\nPayload size: {payload["size"]} bytes')
+        print(f'Base64 data length: {len(payload["data"])} chars')
+        
+        # Test with multiple text payloads
+        print('\n=== Multiple Text Payloads Test ===')
+        multi_test_data = [
+            ('msg1', 'First message', 'text'),
+            ('msg2', 'Second message', 'text'),
+            ('msg3', 'Third message', 'text')
+        ]
+        
+        multi_env, _ = smartsend(
+            TEST_SUBJECT,
+            multi_test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='multi-test-' + correlation_id,
+            is_publish=False
+        )
+        
+        if len(multi_env['payloads']) == 3:
+            print('✅ Multiple payloads handled correctly')
+        else:
+            print(f'❌ Expected 3 payloads, got {len(multi_env["payloads"])}')
+            passed = False
+        
+        # Test size threshold enforcement
+        print('\n=== Size Threshold Test ===')
+        small_text = 'small'
+        large_text = 'x' * (DEFAULT_SIZE_THRESHOLD - 100)  # Just under threshold
+        
+        small_env, _ = smartsend(
+            TEST_SUBJECT,
+            [('small', small_text, 'text')],
+            broker_url=TEST_BROKER_URL,
+            is_publish=False
+        )
+        
+        if small_env['payloads'][0]['transport'] == 'direct':
+            print('✅ Small payload uses direct transport')
+        else:
+            print('❌ Small payload should use direct transport')
+            passed = False
+        
+        # Test that large text (> MAX_PAYLOAD_SIZE) raises error
+        print('\n=== Max Payload Size Test ===')
+        try:
+            too_large_text = 'x' * (MAX_PAYLOAD_SIZE + 1000)
+            large_env, _ = smartsend(
+                TEST_SUBJECT,
+                [('large', too_large_text, 'text')],
+                broker_url=TEST_BROKER_URL,
+                is_publish=False
+            )
+            print('❌ Should have raised MemoryError for payload exceeding MAX_PAYLOAD_SIZE')
+            passed = False
+        except MemoryError as e:
+            print(f'✅ Correctly raised MemoryError: {e}')
+        except Exception as e:
+            print(f'❌ Unexpected error: {type(e).__name__}: {e}')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    run_test()

test/test_py_binary_receiver.py

@@ -0,0 +1,184 @@
+"""
+Python Binary Receiver Test
+Tests the smartreceive function with binary/image/audio/video/table payloads
+"""
+
+import asyncio
+import sys
+import os
+import json
+import base64
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartreceive, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Binary Receiver Test ===\n')
+    
+    # Create mock NATS message with binary payloads
+    image_data = bytes([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A])  # PNG header
+    audio_data = bytes([0x46, 0x4C, 0x41, 0x43, 0x00, 0x00, 0x00, 0x00])  # FLAC header
+    video_data = bytes([0x00, 0x00, 0x00, 0x18, 0x66, 0x74, 0x79, 0x70])  # MP4 header
+    generic_binary = bytes([0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE])
+    
+    test_data = {
+        'correlation_id': 'py-binary-receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+        'msg_id': 'msg-' + str(asyncio.get_event_loop().time() * 1000000),
+        'timestamp': asyncio.get_event_loop().time().isoformat(),
+        'send_to': '/test/binary',
+        'msg_purpose': 'test',
+        'sender_name': 'py-binary-test',
+        'sender_id': 'sender-' + str(asyncio.get_event_loop().time() * 1000000),
+        'receiver_name': 'py-receiver',
+        'receiver_id': 'receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+        'reply_to': '',
+        'reply_to_msg_id': '',
+        'broker_url': TEST_BROKER_URL,
+        'metadata': {},
+        'payloads': [
+            {
+                'id': 'payload-1',
+                'dataname': 'image',
+                'payload_type': 'image',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(image_data),
+                'data': base64.b64encode(image_data).decode('ascii'),
+                'metadata': {'payload_bytes': len(image_data)}
+            },
+            {
+                'id': 'payload-2',
+                'dataname': 'audio',
+                'payload_type': 'audio',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(audio_data),
+                'data': base64.b64encode(audio_data).decode('ascii'),
+                'metadata': {'payload_bytes': len(audio_data)}
+            },
+            {
+                'id': 'payload-3',
+                'dataname': 'video',
+                'payload_type': 'video',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(video_data),
+                'data': base64.b64encode(video_data).decode('ascii'),
+                'metadata': {'payload_bytes': len(video_data)}
+            },
+            {
+                'id': 'payload-4',
+                'dataname': 'binary',
+                'payload_type': 'binary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(generic_binary),
+                'data': base64.b64encode(generic_binary).decode('ascii'),
+                'metadata': {'payload_bytes': len(generic_binary)}
+            }
+        ]
+    }
+    
+    mock_msg = {
+        'payload': json.dumps(test_data)
+    }
+    
+    print('Mock Message Created:')
+    print(f'  Correlation ID: {test_data["correlation_id"]}')
+    print(f'  Payloads: {len(test_data["payloads"])}')
+    print(f'  Payload types: {", ".join(p["payload_type"] for p in test_data["payloads"])}\n')
+    
+    try:
+        # Receive and process the message
+        print('Receiving and processing message...')
+        env = await smartreceive(
+            mock_msg,
+            max_retries=3,
+            base_delay=100,
+            max_delay=1000
+        )
+        
+        print('\n=== Received Envelope ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate received data
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Expected data
+        expected_data = [
+            ('image', image_data, 'image'),
+            ('audio', audio_data, 'audio'),
+            ('video', video_data, 'video'),
+            ('binary', generic_binary, 'binary')
+        ]
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            expected = expected_data[i]
+            
+            if payload[0] != expected[0]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected[0]}', got '{payload[0]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload[2] != expected[2]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected[2]}', got '{payload[2]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            # Verify binary data integrity
+            received_data = payload[1]
+            if not isinstance(received_data, (bytes, bytearray)):
+                print(f'❌ Payload {i + 1}: Expected bytes/bytearray, got {type(received_data)}')
+                passed = False
+            elif received_data != expected[1]:
+                print(f'❌ Payload {i + 1}: Data mismatch')
+                print(f'   Expected: {expected[1]}')
+                print(f'   Got: {received_data}')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data correctly deserialized')
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_binary_sender.py

@@ -0,0 +1,183 @@
+"""
+Python Binary Sender Test
+Tests the smartsend function with binary/image/audio/video/table payloads
+"""
+
+import asyncio
+import sys
+import os
+import base64
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_SUBJECT = '/test/binary'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Binary Sender Test ===\n')
+    
+    correlation_id = 'py-binary-test-' + str(asyncio.get_event_loop().time() * 1000000)
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}\n')
+    
+    # Test data - binary data for different types
+    image_data = bytes([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A])  # PNG header
+    audio_data = bytes([0x46, 0x4C, 0x41, 0x43, 0x00, 0x00, 0x00, 0x00])  # FLAC header
+    video_data = bytes([0x00, 0x00, 0x00, 0x18, 0x66, 0x74, 0x79, 0x70])  # MP4 header
+    generic_binary = bytes([0xDE, 0xAD, 0xBE, 0xEF, 0xCA, 0xFE, 0xBA, 0xBE])
+    
+    # Test table data
+    try:
+        import pandas as pd
+        table_data = pd.DataFrame({
+            'id': [1, 2, 3, 4, 5],
+            'name': ['Alice', 'Bob', 'Charlie', 'David', 'Eve'],
+            'value': [10.5, 20.3, 30.1, 40.9, 50.7]
+        })
+        table_available = True
+    except ImportError:
+        table_available = False
+        table_data = None
+    
+    test_data = [
+        ('image', image_data, 'image'),
+        ('audio', audio_data, 'audio'),
+        ('video', video_data, 'video'),
+        ('binary', generic_binary, 'binary')
+    ]
+    
+    if table_available:
+        test_data.append(('table', table_data, 'table'))
+    
+    try:
+        # Send the message
+        print('Sending binary payloads...')
+        env, env_json_str = await smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='py-binary-test',
+            is_publish=False
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        expected_count = 5 if table_available else 4
+        if len(env['payloads']) != expected_count:
+            print(f'❌ Expected {expected_count} payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Test each payload
+        expected_datanames = ['image', 'audio', 'video', 'binary']
+        expected_types = ['image', 'audio', 'video', 'binary']
+        expected_data = [image_data, audio_data, video_data, generic_binary]
+        
+        if table_available:
+            expected_datanames.append('table')
+            expected_types.append('table')
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            
+            if payload['dataname'] != expected_datanames[i]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected_datanames[i]}', got '{payload['dataname']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload['payload_type'] != expected_types[i]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected_types[i]}', got '{payload['payload_type']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            if payload['transport'] != 'direct':
+                print(f"❌ Payload {i + 1}: Expected transport 'direct', got '{payload['transport']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct transport')
+            
+            if payload['encoding'] != 'base64':
+                print(f"❌ Payload {i + 1}: Expected encoding 'base64', got '{payload['encoding']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct encoding')
+            
+            # Decode and verify the data
+            decoded_data = base64.b64decode(payload['data'])
+            
+            if i < len(expected_data):
+                original_data = expected_data[i]
+                if decoded_data != original_data:
+                    print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                    passed = False
+                else:
+                    print(f'✅ Payload {i + 1}: Data integrity verified')
+            else:
+                # Table payload - just verify it's present
+                print(f'✅ Payload {i + 1}: Table data present (size: {payload["size"]} bytes)')
+            
+            print(f'   Size: {payload["size"]} bytes\n')
+        
+        # Test with larger binary data
+        print('=== Large Binary Data Test ===')
+        large_data = bytes([0xFF] * 10000)  # 10KB of binary data
+        large_test_data = [
+            ('large_binary', large_data, 'binary')
+        ]
+        
+        large_env, _ = await smartsend(
+            TEST_SUBJECT,
+            large_test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='large-' + correlation_id,
+            is_publish=False
+        )
+        
+        if len(large_env['payloads']) == 1 and large_env['payloads'][0]['size'] == 10000:
+            print('✅ Large binary data handled correctly')
+        else:
+            print('❌ Large binary data handling failed')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_dictionary_receiver.py

@@ -0,0 +1,220 @@
+"""
+Python Dictionary Receiver Test
+Tests the smartreceive function with dictionary payloads
+"""
+
+import asyncio
+import sys
+import os
+import json
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartreceive, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Dictionary Receiver Test ===\n')
+    
+    # Create a mock NATS message with dictionary payloads
+    import base64
+    
+    simple_dict = {'key1': 'value1', 'key2': 'value2'}
+    nested_dict = {'outer': {'inner': 'value', 'number': 42}}
+    array_dict = {'items': [1, 2, 3, 'four', 'five']}
+    mixed_dict = {'string': 'text', 'number': 123, 'boolean': True, 'null_val': None}
+    
+    test_data = {
+        'correlation_id': 'py-receiver-dict-' + str(asyncio.get_event_loop().time() * 1000000),
+        'msg_id': 'msg-' + str(asyncio.get_event_loop().time() * 1000000),
+        'timestamp': asyncio.get_event_loop().time().isoformat(),
+        'send_to': '/test/dictionary',
+        'msg_purpose': 'test',
+        'sender_name': 'py-dict-test',
+        'sender_id': 'sender-' + str(asyncio.get_event_loop().time() * 1000000),
+        'receiver_name': 'py-receiver',
+        'receiver_id': 'receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+        'reply_to': '',
+        'reply_to_msg_id': '',
+        'broker_url': TEST_BROKER_URL,
+        'metadata': {},
+        'payloads': [
+            {
+                'id': 'payload-1',
+                'dataname': 'simple_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(simple_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(simple_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(simple_dict).encode('utf8'))}
+            },
+            {
+                'id': 'payload-2',
+                'dataname': 'nested_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(nested_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(nested_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(nested_dict).encode('utf8'))}
+            },
+            {
+                'id': 'payload-3',
+                'dataname': 'array_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(array_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(array_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(array_dict).encode('utf8'))}
+            },
+            {
+                'id': 'payload-4',
+                'dataname': 'mixed_dict',
+                'payload_type': 'dictionary',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(json.dumps(mixed_dict).encode('utf8')),
+                'data': base64.b64encode(json.dumps(mixed_dict).encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(json.dumps(mixed_dict).encode('utf8'))}
+            }
+        ]
+    }
+    
+    mock_msg = {
+        'payload': json.dumps(test_data)
+    }
+    
+    print('Mock Message Created:')
+    print(f'  Correlation ID: {test_data["correlation_id"]}')
+    print(f'  Payloads: {len(test_data["payloads"])}')
+    print(f'  Payload types: {", ".join(p["payload_type"] for p in test_data["payloads"])}\n')
+    
+    try:
+        # Receive and process the message
+        print('Receiving and processing message...')
+        env = await smartreceive(
+            mock_msg,
+            max_retries=3,
+            base_delay=100,
+            max_delay=1000
+        )
+        
+        print('\n=== Received Envelope ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate received data
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Expected data
+        expected_data = [
+            ('simple_dict', simple_dict, 'dictionary'),
+            ('nested_dict', nested_dict, 'dictionary'),
+            ('array_dict', array_dict, 'dictionary'),
+            ('mixed_dict', mixed_dict, 'dictionary')
+        ]
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            expected = expected_data[i]
+            
+            if payload[0] != expected[0]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected[0]}', got '{payload[0]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload[2] != expected[2]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected[2]}', got '{payload[2]}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            data_match = json.dumps(payload[1], sort_keys=True) == json.dumps(expected[1], sort_keys=True)
+            if not data_match:
+                print(f'❌ Payload {i + 1}: Data mismatch')
+                print(f'   Expected: {json.dumps(expected[1], sort_keys=True)}')
+                print(f'   Got: {json.dumps(payload[1], sort_keys=True)}')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data correctly deserialized')
+        
+        # Test round-trip with receive
+        print('\n=== Round-trip Test ===')
+        round_trip_data = {
+            'correlation_id': 'roundtrip-' + str(asyncio.get_event_loop().time() * 1000000),
+            'msg_id': 'msg-' + str(asyncio.get_event_loop().time() * 1000000),
+            'timestamp': asyncio.get_event_loop().time().isoformat(),
+            'send_to': '/test/dictionary',
+            'msg_purpose': 'test',
+            'sender_name': 'py-test',
+            'sender_id': 'sender-' + str(asyncio.get_event_loop().time() * 1000000),
+            'receiver_name': 'py-receiver',
+            'receiver_id': 'receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+            'reply_to': '',
+            'reply_to_msg_id': '',
+            'broker_url': TEST_BROKER_URL,
+            'metadata': {},
+            'payloads': [
+                {
+                    'id': 'payload-rt',
+                    'dataname': 'roundtrip',
+                    'payload_type': 'dictionary',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': len(json.dumps({'test': 'data', 'nested': {'a': 1, 'b': 2}}).encode('utf8')),
+                    'data': base64.b64encode(json.dumps({'test': 'data', 'nested': {'a': 1, 'b': 2}}).encode('utf8')).decode('ascii'),
+                    'metadata': {'payload_bytes': len(json.dumps({'test': 'data', 'nested': {'a': 1, 'b': 2}}).encode('utf8'))}
+                }
+            ]
+        }
+        
+        mock_rt_msg = {'payload': json.dumps(round_trip_data)}
+        rt_env = await smartreceive(mock_rt_msg)
+        
+        if rt_env['payloads'][0][0] == 'roundtrip' and rt_env['payloads'][0][2] == 'dictionary':
+            print('✅ Round-trip test successful')
+        else:
+            print('❌ Round-trip test failed')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_dictionary_sender.py

@@ -0,0 +1,172 @@
+"""
+Python Dictionary Sender Test
+Tests the smartsend function with dictionary payloads
+"""
+
+import asyncio
+import sys
+import os
+import json
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_SUBJECT = '/test/dictionary'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Dictionary Sender Test ===\n')
+    
+    correlation_id = 'py-dict-test-' + str(asyncio.get_event_loop().time() * 1000000)
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}\n')
+    
+    # Test data - various dictionary structures
+    test_data = [
+        ('simple_dict', {'key1': 'value1', 'key2': 'value2'}, 'dictionary'),
+        ('nested_dict', {'outer': {'inner': 'value', 'number': 42}}, 'dictionary'),
+        ('array_dict', {'items': [1, 2, 3, 'four', 'five']}, 'dictionary'),
+        ('mixed_dict', {'string': 'text', 'number': 123, 'boolean': True, 'null_val': None}, 'dictionary')
+    ]
+    
+    try:
+        # Send the message
+        print('Sending dictionary payloads...')
+        env, env_json_str = await smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='py-dict-test',
+            is_publish=False
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        if len(env['payloads']) != 4:
+            print(f'❌ Expected 4 payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Test each payload
+        expected_datanames = ['simple_dict', 'nested_dict', 'array_dict', 'mixed_dict']
+        expected_types = ['dictionary', 'dictionary', 'dictionary', 'dictionary']
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            
+            if payload['dataname'] != expected_datanames[i]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected_datanames[i]}', got '{payload['dataname']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload['payload_type'] != expected_types[i]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected_types[i]}', got '{payload['payload_type']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            if payload['transport'] != 'direct':
+                print(f"❌ Payload {i + 1}: Expected transport 'direct', got '{payload['transport']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct transport')
+            
+            if payload['encoding'] != 'base64':
+                print(f"❌ Payload {i + 1}: Expected encoding 'base64', got '{payload['encoding']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct encoding')
+            
+            # Decode and verify the data
+            import base64
+            decoded_data = json.loads(base64.b64decode(payload['data']).decode('utf8'))
+            original_data = test_data[i][1]
+            
+            # Normalize for comparison (None vs null, True vs true, etc.)
+            if json.dumps(decoded_data, sort_keys=True) != json.dumps(original_data, sort_keys=True):
+                print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                print(f'   Expected: {json.dumps(original_data)}')
+                print(f'   Got: {json.dumps(decoded_data)}')
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Data integrity verified')
+            
+            print(f'   Size: {payload["size"]} bytes\n')
+        
+        # Test round-trip serialization
+        print('=== Round-trip Serialization Test ===')
+        round_trip_data = [
+            ('roundtrip', {'test': 'data', 'numbers': [1, 2, 3], 'nested': {'a': 1, 'b': 2}}, 'dictionary')
+        ]
+        
+        rt_env, _ = await smartsend(
+            TEST_SUBJECT,
+            round_trip_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='roundtrip-' + correlation_id,
+            is_publish=False
+        )
+        
+        rt_payload = rt_env['payloads'][0]
+        rt_decoded = json.loads(base64.b64decode(rt_payload['data']).decode('utf8'))
+        
+        if json.dumps(rt_decoded, sort_keys=True) == json.dumps(round_trip_data[0][1], sort_keys=True):
+            print('✅ Round-trip serialization successful')
+        else:
+            print('❌ Round-trip serialization failed')
+            passed = False
+        
+        # Test JSON string output
+        print('\n=== JSON String Output Test ===')
+        try:
+            parsed = json.loads(env_json_str)
+            if parsed['correlation_id'] == env['correlation_id'] and \
+               len(parsed['payloads']) == len(env['payloads']):
+                print('✅ JSON string is valid and matches envelope')
+            else:
+                print('❌ JSON string does not match envelope')
+                passed = False
+        except json.JSONDecodeError as e:
+            print(f'❌ JSON string is invalid: {e}')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_mix_payloads_sender.py

@@ -0,0 +1,199 @@
+"""
+Python Mix Payloads Sender Test
+Tests the smartsend function with mixed payload types
+"""
+
+import asyncio
+import sys
+import os
+import base64
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_SUBJECT = '/test/mix'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Mix Payloads Sender Test ===\n')
+    
+    correlation_id = 'py-mix-test-' + str(asyncio.get_event_loop().time() * 1000000)
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}\n')
+    
+    # Test data - mixed payload types
+    text_data = 'Hello, NATSBridge!'
+    dict_data = {'key1': 'value1', 'key2': 42, 'nested': {'a': 1, 'b': 2}}
+    image_data = bytes([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A])  # PNG header
+    
+    # Table data
+    try:
+        import pandas as pd
+        table_data = pd.DataFrame({
+            'id': [1, 2, 3],
+            'name': ['Alice', 'Bob', 'Charlie'],
+            'age': [30, 25, 35]
+        })
+        table_available = True
+    except ImportError:
+        table_available = False
+        table_data = None
+    
+    test_data = [
+        ('message', text_data, 'text'),
+        ('config', dict_data, 'dictionary'),
+        ('image', image_data, 'image')
+    ]
+    
+    if table_available:
+        test_data.append(('users', table_data, 'table'))
+    
+    try:
+        # Send the message
+        print('Sending mixed payloads...')
+        env, env_json_str = await smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='py-mix-test',
+            is_publish=False
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        expected_count = 4 if table_available else 3
+        if len(env['payloads']) != expected_count:
+            print(f'❌ Expected {expected_count} payloads, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        # Test each payload
+        expected_datanames = ['message', 'config', 'image']
+        expected_types = ['text', 'dictionary', 'image']
+        expected_data = [text_data, dict_data, image_data]
+        
+        if table_available:
+            expected_datanames.append('users')
+            expected_types.append('table')
+        
+        for i in range(len(env['payloads'])):
+            payload = env['payloads'][i]
+            
+            if payload['dataname'] != expected_datanames[i]:
+                print(f"❌ Payload {i + 1}: Expected dataname '{expected_datanames[i]}', got '{payload['dataname']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct dataname')
+            
+            if payload['payload_type'] != expected_types[i]:
+                print(f"❌ Payload {i + 1}: Expected type '{expected_types[i]}', got '{payload['payload_type']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct type')
+            
+            if payload['transport'] != 'direct':
+                print(f"❌ Payload {i + 1}: Expected transport 'direct', got '{payload['transport']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct transport')
+            
+            if payload['encoding'] != 'base64':
+                print(f"❌ Payload {i + 1}: Expected encoding 'base64', got '{payload['encoding']}'")
+                passed = False
+            else:
+                print(f'✅ Payload {i + 1}: Correct encoding')
+            
+            # Verify data integrity based on type
+            decoded_data = base64.b64decode(payload['data'])
+            
+            if expected_types[i] == 'text':
+                decoded_text = decoded_data.decode('utf8')
+                if decoded_text != expected_data[i]:
+                    print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                    passed = False
+                else:
+                    print(f'✅ Payload {i + 1}: Data integrity verified')
+            elif expected_types[i] == 'dictionary':
+                import json
+                decoded_dict = json.loads(decoded_data.decode('utf8'))
+                if json.dumps(decoded_dict, sort_keys=True) != json.dumps(expected_data[i], sort_keys=True):
+                    print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                    passed = False
+                else:
+                    print(f'✅ Payload {i + 1}: Data integrity verified')
+            elif expected_types[i] == 'image':
+                if decoded_data != expected_data[i]:
+                    print(f'❌ Payload {i + 1}: Data integrity mismatch')
+                    passed = False
+                else:
+                    print(f'✅ Payload {i + 1}: Data integrity verified')
+            elif expected_types[i] == 'table':
+                if len(decoded_data) > 0:
+                    print(f'✅ Payload {i + 1}: Arrow IPC data present ({len(decoded_data)} bytes)')
+                else:
+                    print(f'❌ Payload {i + 1}: Arrow IPC data is empty')
+                    passed = False
+            
+            print(f'   Size: {payload["size"]} bytes\n')
+        
+        # Test with chat-like payload (text + image + audio)
+        print('=== Chat-like Payload Test ===')
+        chat_data = [
+            ('text', 'Hello!', 'text'),
+            ('image', bytes([0xFF, 0xD8, 0xFF, 0xE0]), 'image'),
+            ('audio', bytes([0x46, 0x4C, 0x41, 0x43]), 'audio')
+        ]
+        
+        chat_env, _ = await smartsend(
+            TEST_SUBJECT,
+            chat_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='chat-' + correlation_id,
+            is_publish=False
+        )
+        
+        if len(chat_env['payloads']) == 3:
+            print('✅ Chat-like payloads handled correctly')
+        else:
+            print('❌ Chat-like payloads handling failed')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_table_sender.py

@@ -0,0 +1,167 @@
+"""
+Python Table Sender Test
+Tests the smartsend function with table (Arrow IPC) payloads
+"""
+
+import asyncio
+import sys
+import os
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_SUBJECT = '/test/table'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Table Sender Test ===\n')
+    
+    correlation_id = 'py-table-test-' + str(asyncio.get_event_loop().time() * 1000000)
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}\n')
+    
+    # Test data - pandas DataFrame
+    try:
+        import pandas as pd
+        table_data = pd.DataFrame({
+            'id': [1, 2, 3, 4, 5],
+            'name': ['Alice', 'Bob', 'Charlie', 'David', 'Eve'],
+            'age': [30, 25, 35, 28, 32],
+            'active': [True, False, True, True, False]
+        })
+        table_available = True
+    except ImportError:
+        print('❌ pandas not available - skipping table tests')
+        sys.exit(0)
+    
+    test_data = [
+        ('users_table', table_data, 'table')
+    ]
+    
+    try:
+        # Send the message
+        print('Sending table payload...')
+        env, env_json_str = await smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='py-table-test',
+            is_publish=False
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        if len(env['payloads']) != 1:
+            print(f'❌ Expected 1 payload, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        payload = env['payloads'][0]
+        if payload['dataname'] != 'users_table':
+            print(f"❌ Expected dataname 'users_table', got '{payload['dataname']}'")
+            passed = False
+        else:
+            print('✅ Correct dataname')
+        
+        if payload['payload_type'] != 'table':
+            print(f"❌ Expected payload_type 'table', got '{payload['payload_type']}'")
+            passed = False
+        else:
+            print('✅ Correct payload_type')
+        
+        if payload['transport'] != 'direct':
+            print(f"❌ Expected transport 'direct', got '{payload['transport']}'")
+            passed = False
+        else:
+            print('✅ Correct transport')
+        
+        if payload['encoding'] != 'base64':
+            print(f"❌ Expected encoding 'base64', got '{payload['encoding']}'")
+            passed = False
+        else:
+            print('✅ Correct encoding')
+        
+        print(f'\nPayload size: {payload["size"]} bytes')
+        
+        # Test with larger table
+        print('\n=== Larger Table Test ===')
+        large_table_data = pd.DataFrame({
+            'id': range(100),
+            'name': [f'User{i}' for i in range(100)],
+            'age': [20 + (i % 50) for i in range(100)],
+            'active': [i % 2 == 0 for i in range(100)]
+        })
+        
+        large_test_data = [
+            ('large_table', large_table_data, 'table')
+        ]
+        
+        large_env, _ = await smartsend(
+            TEST_SUBJECT,
+            large_test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='large-' + correlation_id,
+            is_publish=False
+        )
+        
+        if len(large_env['payloads']) == 1:
+            print('✅ Large table handled correctly')
+            print(f'   Size: {large_env["payloads"][0]["size"]} bytes')
+        else:
+            print('❌ Large table handling failed')
+            passed = False
+        
+        # Test JSON string output
+        print('\n=== JSON String Output Test ===')
+        import json
+        try:
+            parsed = json.loads(env_json_str)
+            if parsed['correlation_id'] == env['correlation_id'] and \
+               len(parsed['payloads']) == len(env['payloads']):
+                print('✅ JSON string is valid and matches envelope')
+            else:
+                print('❌ JSON string does not match envelope')
+                passed = False
+        except json.JSONDecodeError as e:
+            print(f'❌ JSON string is invalid: {e}')
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_text_receiver.py

@@ -0,0 +1,205 @@
+"""
+Python Text Receiver Test
+Tests the smartreceive function with text payloads
+"""
+
+import asyncio
+import sys
+import os
+import json
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartreceive, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Text Receiver Test ===\n')
+    
+    # Create a mock NATS message with text payload
+    test_text = 'Hello, NATSBridge! This is a test message.'
+    import base64
+    
+    test_data = {
+        'correlation_id': 'py-receiver-test-' + str(asyncio.get_event_loop().time() * 1000000),
+        'msg_id': 'msg-' + str(asyncio.get_event_loop().time() * 1000000),
+        'timestamp': asyncio.get_event_loop().time().isoformat(),
+        'send_to': '/test/text',
+        'msg_purpose': 'test',
+        'sender_name': 'py-text-test',
+        'sender_id': 'sender-' + str(asyncio.get_event_loop().time() * 1000000),
+        'receiver_name': 'py-receiver',
+        'receiver_id': 'receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+        'reply_to': '',
+        'reply_to_msg_id': '',
+        'broker_url': TEST_BROKER_URL,
+        'metadata': {},
+        'payloads': [
+            {
+                'id': 'payload-' + str(asyncio.get_event_loop().time() * 1000000),
+                'dataname': 'message',
+                'payload_type': 'text',
+                'transport': 'direct',
+                'encoding': 'base64',
+                'size': len(test_text.encode('utf8')),
+                'data': base64.b64encode(test_text.encode('utf8')).decode('ascii'),
+                'metadata': {'payload_bytes': len(test_text.encode('utf8'))}
+            }
+        ]
+    }
+    
+    mock_msg = {
+        'payload': json.dumps(test_data)
+    }
+    
+    print('Mock Message Created:')
+    print(f'  Correlation ID: {test_data["correlation_id"]}')
+    print(f'  Payloads: {len(test_data["payloads"])}')
+    print(f'  Payload dataname: {test_data["payloads"][0]["dataname"]}')
+    print(f'  Payload type: {test_data["payloads"][0]["payload_type"]}')
+    print(f'  Transport: {test_data["payloads"][0]["transport"]}\n')
+    
+    try:
+        # Receive and process the message
+        print('Receiving and processing message...')
+        env = await smartreceive(
+            mock_msg,
+            max_retries=3,
+            base_delay=100,
+            max_delay=1000
+        )
+        
+        print('\n=== Received Envelope ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate received data
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if len(env['payloads']) != 1:
+            print(f'❌ Expected 1 payload, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        payload = env['payloads'][0]
+        if payload[0] != 'message':
+            print(f"❌ Expected dataname 'message', got '{payload[0]}'")
+            passed = False
+        else:
+            print('✅ Correct dataname')
+        
+        if payload[2] != 'text':
+            print(f"❌ Expected type 'text', got '{payload[2]}'")
+            passed = False
+        else:
+            print('✅ Correct type')
+        
+        if payload[1] != test_text:
+            print('❌ Data mismatch')
+            print(f'   Expected: {test_text}')
+            print(f'   Got: {payload[1]}')
+            passed = False
+        else:
+            print('✅ Data correctly deserialized')
+        
+        # Test with multiple text payloads
+        print('\n=== Multiple Text Payloads Test ===')
+        multi_test_data = {
+            'correlation_id': 'multi-receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+            'msg_id': 'msg-' + str(asyncio.get_event_loop().time() * 1000000),
+            'timestamp': asyncio.get_event_loop().time().isoformat(),
+            'send_to': '/test/text',
+            'msg_purpose': 'test',
+            'sender_name': 'py-text-test',
+            'sender_id': 'sender-' + str(asyncio.get_event_loop().time() * 1000000),
+            'receiver_name': 'py-receiver',
+            'receiver_id': 'receiver-' + str(asyncio.get_event_loop().time() * 1000000),
+            'reply_to': '',
+            'reply_to_msg_id': '',
+            'broker_url': TEST_BROKER_URL,
+            'metadata': {},
+            'payloads': [
+                {
+                    'id': 'payload-1',
+                    'dataname': 'msg1',
+                    'payload_type': 'text',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': 16,
+                    'data': base64.b64encode(b'First message').decode('ascii'),
+                    'metadata': {'payload_bytes': 16}
+                },
+                {
+                    'id': 'payload-2',
+                    'dataname': 'msg2',
+                    'payload_type': 'text',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': 16,
+                    'data': base64.b64encode(b'Second message').decode('ascii'),
+                    'metadata': {'payload_bytes': 16}
+                },
+                {
+                    'id': 'payload-3',
+                    'dataname': 'msg3',
+                    'payload_type': 'text',
+                    'transport': 'direct',
+                    'encoding': 'base64',
+                    'size': 16,
+                    'data': base64.b64encode(b'Third message').decode('ascii'),
+                    'metadata': {'payload_bytes': 16}
+                }
+            ]
+        }
+        
+        mock_multi_msg = {'payload': json.dumps(multi_test_data)}
+        multi_env = await smartreceive(mock_multi_msg)
+        
+        if len(multi_env['payloads']) == 3:
+            print('✅ Multiple payloads handled correctly')
+            
+            # Verify each payload
+            expected_messages = ['First message', 'Second message', 'Third message']
+            for i in range(3):
+                if multi_env['payloads'][i][1] == expected_messages[i]:
+                    print(f'✅ Payload {i + 1} correctly deserialized')
+                else:
+                    print(f'❌ Payload {i + 1} mismatch')
+                    passed = False
+        else:
+            print(f"❌ Expected 3 payloads, got {len(multi_env['payloads'])}")
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())

test/test_py_text_sender.py

@@ -0,0 +1,164 @@
+"""
+Python Text Sender Test
+Tests the smartsend function with text payloads
+"""
+
+import asyncio
+import sys
+import os
+
+# Add parent directory to path
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from natsbridge import smartsend, DEFAULT_BROKER_URL, DEFAULT_FILESERVER_URL
+
+TEST_SUBJECT = '/test/text'
+TEST_BROKER_URL = os.environ.get('NATS_URL', 'nats://localhost:4222')
+TEST_FILESERVER_URL = os.environ.get('FILESERVER_URL', 'http://localhost:8080')
+
+
+async def run_test():
+    print('=== Python Text Sender Test ===\n')
+    
+    correlation_id = 'py-text-test-' + str(asyncio.get_event_loop().time() * 1000000)
+    print(f'Correlation ID: {correlation_id}')
+    print(f'Subject: {TEST_SUBJECT}')
+    print(f'Broker URL: {TEST_BROKER_URL}\n')
+    
+    # Test data
+    text_data = 'Hello, NATSBridge! This is a test message.'
+    test_data = [
+        ('message', text_data, 'text')
+    ]
+    
+    try:
+        # Send the message
+        print('Sending text payload...')
+        env, env_json_str = await smartsend(
+            TEST_SUBJECT,
+            test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id=correlation_id,
+            msg_purpose='test',
+            sender_name='py-text-test',
+            is_publish=False  # Don't actually publish for this test
+        )
+        
+        print('\n=== Envelope Created ===')
+        print(f'Correlation ID: {env["correlation_id"]}')
+        print(f'Message ID: {env["msg_id"]}')
+        print(f'Timestamp: {env["timestamp"]}')
+        print(f'Subject: {env["send_to"]}')
+        print(f'Purpose: {env["msg_purpose"]}')
+        print(f'Sender: {env["sender_name"]}')
+        print(f'Payloads: {len(env["payloads"])}\n')
+        
+        # Validate envelope structure
+        print('=== Validation ===')
+        passed = True
+        
+        if not env.get('correlation_id'):
+            print('❌ correlation_id is missing')
+            passed = False
+        else:
+            print('✅ correlation_id present')
+        
+        if not env.get('msg_id'):
+            print('❌ msg_id is missing')
+            passed = False
+        else:
+            print('✅ msg_id present')
+        
+        if not env.get('timestamp'):
+            print('❌ timestamp is missing')
+            passed = False
+        else:
+            print('✅ timestamp present')
+        
+        if len(env['payloads']) != 1:
+            print(f'❌ Expected 1 payload, got {len(env["payloads"])}')
+            passed = False
+        else:
+            print('✅ Correct number of payloads')
+        
+        payload = env['payloads'][0]
+        if payload['dataname'] != 'message':
+            print(f"❌ Expected dataname 'message', got '{payload['dataname']}'")
+            passed = False
+        else:
+            print('✅ Correct dataname')
+        
+        if payload['payload_type'] != 'text':
+            print(f"❌ Expected payload_type 'text', got '{payload['payload_type']}'")
+            passed = False
+        else:
+            print('✅ Correct payload_type')
+        
+        if payload['transport'] != 'direct':
+            print(f"❌ Expected transport 'direct', got '{payload['transport']}'")
+            passed = False
+        else:
+            print('✅ Correct transport')
+        
+        if payload['encoding'] != 'base64':
+            print(f"❌ Expected encoding 'base64', got '{payload['encoding']}'")
+            passed = False
+        else:
+            print('✅ Correct encoding')
+        
+        # Decode and verify the data
+        import base64
+        decoded_data = base64.b64decode(payload['data']).decode('utf8')
+        if decoded_data != text_data:
+            print('❌ Decoded data mismatch')
+            print(f'   Expected: {text_data}')
+            print(f'   Got: {decoded_data}')
+            passed = False
+        else:
+            print('✅ Data integrity verified')
+        
+        print(f"\nPayload size: {payload['size']} bytes")
+        print(f'Base64 data length: {len(payload["data"])} chars')
+        
+        # Test with multiple text payloads
+        print('\n=== Multiple Text Payloads Test ===')
+        multi_test_data = [
+            ('msg1', 'First message', 'text'),
+            ('msg2', 'Second message', 'text'),
+            ('msg3', 'Third message', 'text')
+        ]
+        
+        multi_env, _ = await smartsend(
+            TEST_SUBJECT,
+            multi_test_data,
+            broker_url=TEST_BROKER_URL,
+            fileserver_url=TEST_FILESERVER_URL,
+            correlation_id='multi-test-' + correlation_id,
+            is_publish=False
+        )
+        
+        if len(multi_env['payloads']) == 3:
+            print('✅ Multiple payloads handled correctly')
+        else:
+            print(f"❌ Expected 3 payloads, got {len(multi_env['payloads'])}")
+            passed = False
+        
+        # Final result
+        print('\n=== Test Result ===')
+        if passed:
+            print('✅ ALL TESTS PASSED')
+            sys.exit(0)
+        else:
+            print('❌ SOME TESTS FAILED')
+            sys.exit(1)
+            
+    except Exception as e:
+        print(f'❌ Test failed with error: {e}')
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    asyncio.run(run_test())